Correlation and Heritability Analysis for Seed Quality under Controlled Conditions in Wheat (Triticum aestivum L.)

A study was conducted on wheat (Triticum aestivum L.) in laboratory at Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya, Uttar Pradesh, during the 2019–20 for correlation and heritability analysis for seed quality under controlled conditions in wheat. In a wheat crop research, 30 germplasm were tested using three checks each for the parameters of seed weight, seed width, seed length, shoot length, root length, seedling length, seedling dry weight, germination (%), first count, final count, and vigour index-I and vigour index-II. In this study, the germplasm was assessed using parameters and the correlation coefficient. The vigour index-II demonstrated a very significant positive phenotypic connection with root length (0.828), final count (0.564), and first count (0.552), as well as a genotypically significant positive correlation with final count (1.165), root length (0.867), and first count (0.552). The high estimates (>15%) of phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) were registered in the case of vigour index-I (PCV=17.36%, GCV=17.24%), shoot length (PCV=15.96%, GCV= 15.77%), seed width (PCV= 15.35%, GCV= 15.19%). The moderate estimate (10%) of PCV and GCV were recorded for root length (PCV=12.72%, GCV=12.56%), and seedling length (PCV= 11.46, GCV= 11.30).

Heterosis Exploration in Single-Cross Inbred Line Combinations of Maize (Zea mays L.)

This study evaluates 56 crosses generated through the Line × Tester mating pattern using seeds collected during the kharif season of 2022 from the Post Graduation research Farm at Lovely Professional University (LPU), Punjab's Post Graduate Research Farm during the 2022 kharif season. In addition to the hybrids, fifteen parent lines and one check were grown. The experiment was conducted using a Randomized Block Design (RBD) with three replications in the 2023 kharif season. Significant disparities between the entries were found by analyzing the mean squares for 11 attributes. Out of all the crosses, the hybrid BPPT1 x BML20 showed the greatest standard heterosis; BML6 x BML3 ranked second in terms of grain yield per plant. Crucially, these hybrids showed noteworthy and desired standard heterosis for other characteristics as well as grain production, suggesting that they might lead to improved overall performance. Using heterosis in maize might result in better cross combinations, meeting the increasing demand for the grain due to its bioactive qualities. The results of this study can help breeders create robust and high yielding varieties of maize, promoting sustainable agriculture and guaranteeing food security in the face of changing environmental issues. The findings of this research can guide breeders in developing high yielding and resilient maize varieties, contributing to sustainable agriculture, and ensuring food security in the face of evolving environmental challenges.

Effect of Predominant Mycoflora (A. alternata and M. phaseolina) on Seed Quality Parameters of Sesamum

Sesamum is an important oilseed crop affected by toxigenic fungal pathogens viz., Alternaria, Macrophomina, Fusarium and Aspergillus spp. Among these, A. alternata and M. phaseolina are seed borne pathogens causing yield loss to an extent of 20 to 40 per cent. The effect of A. alternata and M. phaseolina on seed quality parameters of susceptible cv. Swetha was investigated during 2022-2023. The A. alternata and M. phaseolina inoculated and uninoculated seeds of both test pathogens were tested for germination and seedling growth by rolled paper method and pot culture studies. Significant differences in seed germination, seedling length, seedling dry mass, seedling vigour index (SVI) - I and II and seed moisture content were observed in susceptible cv. Swetha. The results indicated that A. alternata recorded lower seed germination percentage (60.50%), seedling length (6.56 cm), dry mass (9.12 mg) and SVI-I and II (656 and 552 respectively) over untreated seeds recording high germination (82.25%), seedling length (14.84 cm), dry mass (13.17 mg) and SVI-I and II (1221 and 1116 respectively). Similar results were observed in M. phaseolina treated seeds where the pathogen treated seeds recorded lower seed germination percentage (70.75%), seedling length (9.42 cm), dry mass (8.71 mg) and SVI-I and II (667 and 599 respectively) than pathogen untreated seeds recording high seed germination (82.50%), seedling length (14.25 cm), dry mass (13.30 mg) and SVI-I and II (1175 and 1097 respectively).

In-vitro Screening of EMS and Sodium Azide Induced Mutant Population at Seedling Stage for Drought Tolerance in Wheat (Triticum aestivum L.)

Drought caused by climate change result in water shortages, decreased global wheat production and unevenly distributed heavy rains. About 50% of the global wheat production is affected by water deficit conditions. The effects of different concentrations of EMS and SA on HD-3226 and HI-1620 wheat genotype for drought tolerance capability were investigated at seedling stage under water and osmotic stress conditions. In the present study, 15% concentration of polyethylene glycol (PEG-6000, to mimic drought stress) was used for in-vitro screening of EMS and SA induced mutant lines of both wheat genotypes. Current study revealed that SA decreased germination of seeds, seedling length, seed vigour index and survival rate percentage while it increased morphological mutation frequency percentage as comparison to EMS treatment in both wheat genotypes under water and PEG stress. Moreover, osmotic stress significantly reduced seed germination, shoot length, root length, seed vigour index, survival rate percentage compared to control-wild type.

Impact of Sowing Pattern and Seed Rate on Quality of Wheat Seed

Wheat (Triticum aestivum L.) is the world's most essential staple food. It is the most important crop in Himachal Pradesh during the winter season in the state's low and mid hills. Manipulation of agronomic practices such as planting pattern/geometry and seed rate is regarded as the first stage in achieving optimum plant distribution over cultivated area, resulting in greater utilization of above and below ground natural resources. A field and laboratory investigation was undertaken to study the effect of different planting patterns and seed rates on its quality in wheat by evaluating the quality parameters. The experiment with twelve treatment combinations comprising of four planting patterns (P1-15 cm, P2 -23 cm, P3 -15 x 15 cm and P4 -23 x 23 cm) and three seed rates (S1 -100, S2 - 120 and S3 -140 kg/ha) was conducted in Randomized Block Design with four replications during Rabi season of 2015-16 at experimental farm of CSKHPKV, Palampur, Himachal Pradesh, India. Observations showed that 23 × 23 cm planting patterns produced significantly (2.96%) higher 1000 seed weight, (8.08%) seedling length, (6.01%) seedling dry weight, (8.34%) vigour index –I and (6.58%) vigour index- II over normal planting patterns (23 cm), whereas other planting techniques had no appreciable impact on germination percentage. Different seed rates had no appreciable impact on 1000 seed weight, germination rate, seedling length, seedling dry weight, and vigour index. Criss cross sowing (23 x 23 cm) with 140 kg per hectare is the best combination for quality seed production of wheat.

Effect of Different Pre-Sowing Treatments on Germination Characteristics of Strawberry Guava (Psidium cattleainum Sabine)

Aim: The aim of the present study was to investigate the effect of different pre-sowing treatments on germination characteristics of strawberry guava (Psidium cattleainum Sabine).Study Design: The experiment consisted of eleven treatments and three replications laid out in a Completely randomized design (CRD).Place and Duration of Study: The study was conducted at Orchard Nursery, Department of Fruit Science, Horticulture College and Research Institute, Tamil Nadu Agricultural University, Coimbatore during April-June 2023.Methodology: Seeds of Psidium cattleainum (strawberry guava) were collected from guava germplasm from an orchard and treated with different pre-sowing chemicals. After pre-sowing treatment, the seeds were sown and various germination characteristics and growth parameters were observed and recorded.Results: The seeds treated with GA3 500 ppm for 30 minutes took minimum days to germinate (20), with higher germination percentage (79.33%), maximum vigour index I, and vigour index II (708.6 and 584.23). The growth parameters such as seedling height, stem girth,and number of leaves, primary root length, number of lateral roots were recorded higher in GA3 500 ppm followed by Thiourea 1%.The biomass production of seedlings was also higher in seeds treated with GA3 500 ppm.Conclusion: The seeds treated with GA3 500 ppm for 30 minutes recorded higher germination characteristics, growth parameters and biomass production. So for quicker propagation of strawberry guava to be used as rootstock, seeds can be treated with 500 ppm GA3 to obtain the large number of seedlings for the use of rootstock.

CaO Nanoparticles Seed Invigoration on Germination and Seedling Growth of Rice var. TRY 3

Rice (Oryza sativa L.), a vital cereal and staple food crop in South East Asia. It faces significant challenges in cultivation worldwide, due to soil salinity. Seed enhancement techniques like priming have shown resilience against salt stress. In this study, the potential of nano-priming with calcium oxide nanoparticles (CaO NPs) to enhance rice seed germination and growth was investigated. CaO NPs were synthesized from organic waste (eggshells) using a sol-gel technique and characterized using Raman and UV-Vis spectroscopy. Paddy seeds were primed with varying concentrations of CaO NPs, and their germination and seedling growth were assessed. The results showed that nano-priming with 40 ppm of CaO NPs significantly improved germination, root and shoot length, dry matter production, and seedling vigour as compared to the control. However, higher concentrations of CaO NPs had a detrimental effect on germination. The study suggests that CaO NP seed priming has the potential to enhance rice germination and seedling development.

Studies on Heterosis for Fruit Yield, Quality and ToLCV Resistant in Tomato (Solanum lycopersicum L.)

Aims: The current study was designed to investigate the nature and extent of heterosis for marketable fruit output, quality attributes, and resistance to tomato leaf curl virus.Study Design: Statistical Randomized Block Design.Place and Duration of Study: The current study was conducted in Horticulture Research Field at Sam Higginbottom University of Agriculture Technology and Sciences at Prayagraj U.P. India during Rabi, 2016–17.Methodology: The experimental included three testers and thirteen lines During Rabi, 2016–17, out of these, ten lines (female parents) were crossed with every three testers (male parents). The resulting 30 F1s were assessed for yield, fruit quality, and leaf curl virus resistance. To gather data, five plants from each replication were randomly tagged in each entry and analysis of variance was performed. Heterosis over better parent (BP) was calculated by treating each feature using the approach proposed by Hayes et al. [1]. The studied data were statically analyzed using the Indostat software Hyderabad program.Results: The standard heterosis for fruit yield ranged from -67.19 to 29.70% Check (Kashi Abhiman). Five crosses viz., Arka Abha x Kashi Aman, Arka Abha x Kashi Vishesh, Pant T-7 x Kashi Vishesh, S-22 x H-88-78-5 and Pant T-7 x Kashi Aman were exhibited sufficient amount of significant and positive heterosis for fruit yield over standard check. The hybrids Azad T-5 x Kashi Aman and Pant T-7 x Kashi Aman exhibited low incidence with negative heterosis for the ToLCV incidence and severity.Conclusion: Commercialization of hybrid vigor in tomato (Solanum lycopersium L.) has gained prominence due to various advantages of hybrids over pure line varieties, including higher marketable fruit output, component characteristics, and resilience to biotic and abiotic stresses. According to data presented in the study it is concluded that hybrid vigour can obtain by crossing of parents having desirable characters in tomato.

Effect of Seed Testing Temperature on Germination of Bhendi Seed

Temperature is one of the factors which play a major role in deciding the planting value of a seed lot in the seed testing laboratory. The temperature requirement varies with species. High or low temperature may stimulate or inhibit the germination of seeds under testing. The tropical crops may require higher temperature than temperate crops for germination. Eventhough, a seed lot is having high germination and vigour parameter, it could be revealed with suitable seed testing temperature only. Since bhendi is a tropical vegetable crop, two varieties of bhendi, Arka Anamika and CO4 with each five different lots were tested with four different temperature regimes viz., 15, 20, 25 and 30ºC. The experimental results revealed that bhendi seeds performed well at the temperature regime of 30ºC followed by 25ºC which was on par with each other. It was also accompanied with seed quality characteristics of seedling length, vigour index and dry matter production of seedlings. Irrespective of varieties and lots studied, the high temperature showed its superiority over other temperatures. The study also disclosed that the low temperature of 15ºC was not suitable for bhendi seed germination, because none of the seeds produced normal seedling. At low temperature seeds could produce more abnormal seedlings than rest of the temperature regimes studied. It could be inferred that the seed testing temperature suitable for bhendi seed germination is 30°C or 25°C. Low temperature (15°C) is not suitable, since the normal seedlings were not produced at this temperature.

Identification of genomic regions associated with early plant vigour in lentil (Lens culinaris)

Lentil is one of the most important food legume species, however its genetic and genomic resources remained largely uncharacterized and unexploited. In the past few years, a number of genetic maps have been constructed and marker resources have been developed in lentil. These resources could be exploited for understanding the extent and distribution of genetic variation in genus Lens and also for developing saturated and consensus genetic maps suitable for quantitative trait loci (QTL) mapping and marker-assisted selection. The present study aims to enrich polymerase chain reaction-based linkage map of F10 recombinant inbred lines (RILs) population of 94 individuals derived from cross WA8649090 9 Precoz and identification of QTLs linked to early plant vigour traits. Of the 268 polymorphic markers (93 simple sequence repeats (SSR), three inter-simple sequence repeats (ISSRs) and 172 random amplified polymorphic DNA (RAPDs)), 265 (90 SSRs, three ISSRs and 172 RAPDs) were mapped on seven linkage groups, varying in length between 25.6 and 210.3 cM, coverage of 809.4 cM with an average marker spacing of 3.05 cM. The study also reported assigning of 24 new cross-genera SSRs of Trifolium pratense on the present linkage map. The RILs along with the parents were screened for shoot length, root length, seedling length, dry weight, number of leaves and number of branches based on two replications under polyhouse conditions. A QTLhotspot consisting of six QTLs for shoot length (cm), root length (cm) and seedling length (cm) was observed between a map distances of 56.61 and 86.81 cM on LG1.

Effect of Seed Hydropriming on Seedling Emergence and Growth of Chickpea (Cicer arietinum L.) under Adverse Climatic Condition of Drought and Salinity

Aim: Assessment of influence of seed hydropriming in seed and seedling vigour enhancement for stress tolerance in chickpea which is important for successful crop production under erratic climate change causing drought and salinity stress severely affecting the seedling emergence and establishment especially in arid and semi arid regions of the world. Study Design: A three factorial randomised block design was used in the study, involving seed hydropriming treatment, chickpea varieties and growth conditions. Place and Duration of the Study: The experiment was conducted in Department of Seed Science and Technology, University of Agricultural Sciences, Dharwad, India, during the year 2018. Methodology: Six months old chickpea seeds of variety JG-11 and Annigeri-1 were hydroprimed for 12 hours at 25°C in dark condition. The primed and unprimed control seeds are sown under normal, drought and salinity conditions imposed in pots under controlled conditions. The data recorded were analysed for Analysis of Variance (ANNOVA). Results: The result of the experiment revealed that, upon seed hydropriming an average of 19 per cent increase in seedling emergence and 53.3 per cent increase in seedling vigour index was observed as compared to unprimed control seeds irrespective of variety and the abiotic stress conditions.

Characterization of cultural beneficial bacterial diversity for plant growth promoting attributes associated with rice rhizosphere

Aim: The study was undertaken to isolate, characterize and molecularly identify plant growth promoting rhizobacteria (PGPR) associated with rice rhizosphere occurring in Gangetic plains of the country. Methodology: One hundred forty three plant growth promoting rhizobacteria were isolated on various culture media and characterized culturally and morphologically through Scanning Electron Microscope. These rhizobacterial isolates were further screened for plant growth promoting activities like HCN production, siderophore production and phosphate solubilisation. The 16S rDNA sequencing was done to decipher phylogenetic relationship among 19 selected PGPRs. Besides, these were also tested for anti-oxidative enzyme production to mitigate deleterious effects of various stresses on plant growth and metabolism. Results: Nineteen potential plant growth promoting rhizobacteria were characterized for plant growth promoting attributes and were indentified at molecular level. Rice is well colonized by bacteria mainly Bacillus spp., Pseudomonas spp., Burkholderia sp., and Acinetobactor spp., Rice seeds treated with microbial consortium of MAU 143 + MRT 84 recorded in increased antioxidant production–SOD activity (0.02 U mg−1 f.w.t.), POX activity (0.16 U mg−1 f.w.t.), POP activity (0.06 U mg−1 f.w.t.) and TPC assay (1.17 µg gallic acid mg-1 extract) which might have stimulated the growth of radical (2.2 cm) and plumule (1.6 cm) over control. These three PGPRs viz., MAU 143, MRT 84 and MRT 92 strain showed great potential to improve antioxidant and total polyphenol production and seed vigour of rice seedlings. The identified rhizobacterial strains may be used for plant growth promotion and improvement in nutrients mobilization and oxidative stresses in rice production. Interpretation: The study suggested that plant growth promoting rhizobacteria isolated from rice rhizosphere have greater potential to improve soil nutrients status while provide resistance against infection of pathogenic microbes due to production of anti-oxidative enzymes and phenolic compounds in rice seedlings.

Spermine induced protection of onion seed vigour and viability during accelerated ageing

Aim: The aim of the present study was to investigate the role of spermine, a polyamine as a protective agent on accelerated ageing of onion seeds. Methodology: Onion seeds variety Pusa Riddhi was primed with six concentrations of spermine (0.10 mM to 1.25 mM) and also with hydration and halopriming (2% K2HPO4). Hydrated, haloprimed and un-primed seeds were used as control. The primed and control seeds were accelerated aged at 45 oC and 100 % RH for 72 hr. Seed quality was assessed in control, freshly primed seeds, and in primed seeds subjected to accelerate ageing. Results: All priming treatments enhanced the seed quality, there was 2.34–20.33 % increase in germination. Seed priming with 2% K2HPO4 had highest seed quality improvement which was at par with 1.25 mM spermine primed seeds. Enhanced seed vigour and the activity of antioxidant enzymes over un-primed seeds was observed in both 2% K2HPO4 and spermine primed seeds over unprimed seds. Seeds primed with 1.25 mM spermine recorded 66.66 % and 650 % increase in the activity of ROS scavenging enzymes SOD and POD respectively, but they were at par with halopriming. After accelerated ageing, deterioration in seed quality was minimal in seeds primed with spermine. Seeds primed with 1.25 mM spermine recorded 21.33% higher germination, 62.10 % higher speed of germination, 26.56 % longer seedlings, 13.68 % heavier seedlings and 175 % and 200 % higher SOD and POD activity as comparised to un-primed seeds. Seeds primed with 1.25 mM spermine also performed better over halopriming and hydropriming treatments. Interpretation: Onion seed priming with 1.25 mM spermine was most effective treatment in enhancing the seed germination and vigour under accelerated ageing conditions.

Physiological changes in seeds and seedlings of pumpkins submitted to salt stress / Alterações fisiológicas em sementes e mudas de abóboras submetidas a estresse salino

Salinity is one of the most limiting environmental factors for plant growth in semi-arid regions.Excessofsalts reduces water potential, causes physiological drought and can influence germination and initial growth of plants. The objective of this work was to study physiological and metabolic changes in seeds and seedlings of pumpkin (Cucurbita pepo cultivars Caserta and Redonda and C. maxima cv. Coroa)in a saline condition of salt stress. Thus, we it was quantified germination parameters; seedlings growth; seeds and seedlings respiration; degradation of total soluble sugars, reducing sugars and total proteins in cotyledons and the activity ascorbate peroxidase (APX), glutathione-S-transferase (GST) and catalase (CAT) during germination and initial growth of the pumpkin species studied in saline conditions. The experimental design was totally randomized in a factorial scheme 6x3, with six electrical conductivities (0; 2; 4; 6; 8 e 10 dS.m-1) and three cultivars (Redonda, Caserta and Coroa). Salinity did not influence the rate of seed respiration during the germination, although seedlings respiration decreased, as well as its vigour. Total sugars were degraded, while there was accumulation of reducing sugars and proteins in cotyledons of germinating seeds in salt solutions. Increased electrical conductivity reduced APX activity in the embryo and CAT in cotyledons, but did not influence GST. Pumpkin seedlings showed low tolerance to salt stress.

A salinidade é um dos fatores limitantes para o crescimento das culturas nas regiões áridas e semiáridas. O excesso de sais provoca uma redução no potencial hídrico e causa seca fisiológica e influencia na germinação e crescimento inicial de plântulas Objetivou-se estudar possíveis alterações fisiológicas e metabólicas em sementes e plântulas de abóboras (Cucurbita pepo cultivars Caserta and Redonda and C. maxima cv. Coroa), Sendo assim, avaliou-se em sementes e plântulas os parâmetros da germinação (porcentagem e velocidade); crescimento de plântulas; respiração de sementes e plântulas; degradação de açúcar solúveis totais, açúcar redutores e proteínas totais nos cotilédones e atividade das enzimas ascorbato peroxidase (APX), glutationa-S-transferase (GST) e catalase (CAT) durante a germinação e crescimento inicial das cultivares de abóbora em soluções salinas. O delineamento experimental foi inteiramente casualizado em esquema fatorial 6x3, com seis condutividades elétricas (0; 2; 4; 6; 8 e 10 dS.m-1) e três cultivares (Redonda, Caserta e Coroa). A salinidade não influenciou a taxa de respiração das sementes durante a germinação, no entanto, a respiração das plântulas diminuiu, assim como o vigor das plântulas. Houve degradação dos açúcares totais e acúmulo de açúcares redutores e proteínas em cotilédones de sementes submetidas a soluções salinas. O aumento da condutividade elétrica induziu redução da atividade de APX no embrião e de CAT nos cotilédones, mas não influenciou GST. Cultivares de aboboras apresentaram baixa tolerância ao estresse salino.

Influence of Seed Pelleting on Physiological Seed Quality Improvement in Bael (Aegle marmelos (L.) Corr.) the Endangered Medicinal Tree

Aim: Bael is an endangered medicinal tree with multipurpose utility propagated through seeds. Hence attempts were to improve the vigour of the seed through seed pelleting with ecofriently organic products. Study Design: A Factorial completely randomized design (FCRD) for laboratory experiments and RBD for nursery studies with five replication with five replications. Place and Duration of Study: The laboratory and nursery experiment was conducted at the Department of Seed Science and Technology, Tamil Nadu Agricultural University, Coimbatore during 2012-13. Methodology: The seeds were pelleted with botanical leaf powders viz., karisilanganni (Eclipta prostrate), avaram (Cassia auriculata), arappu (Albizia amara), neem (Azadirachta indica), biofertilizers viz., azophos, phosphobacteria and biocontrol agents viz., Trichoderma viride and Pseudomonas fluorescens along with unpelleted seeds. Results: The results showed that among the treatments arappu pelleting enhanced the germination (76%) and seedling quality characters viz., root length (13.0 cm), shoot length (9.9 cm), dry matter production (318 mg) and vigour index (1740) compared to control followed by neem and phosphobacteria pelleting. The treatment scored as best also performed better at polypot nursery. Conclusion: Our data show that arappu pelleting enhanced seed quality compared to control

Viabilidad y germinación de semillas de Hechtiaperotensis (Bromeliaceae) / Viability and germination of Hechtia perotensis (Bromeliaceae) seed

ResumenPoblaciones endémicas de Hechtiaperotensis se han descrito en Puebla y Veracruz, México. La recolección de semillas de buena calidad permite su uso en conservación, investigación y restauración ecológica. Algunos compuestos para evaluar la calidad de las semillas silvestres y endémicas, como nitrato de potasio (KNO3) y ácido giberílico (AG3), se utilizan para incrementar la germinación de las semillas y disminuir la latencia. La prueba de cloruro de trifeniltetrazolio (tetrazolio) se correlaciona con la viabilidad de las semillas porque se basa en la actividad de las deshidrogenasas de tejidos vivos que catalizan la respiración mitocondrial. El objetivo de este estudio fue conocer el tamaño y el peso de las cápsulas y las semillas y la germinación y viabilidad de las semillas de H. perotensis recolectadas en Veracruz en 2012 y 2015. Las hipótesis fueron (1) que la germinación y la viabilidad de las semillas son independientes del año de recolecta, (2) que hay una concentración adecuada de tetrazolio para identificar la viabilidad de las semillas y (3) que el pretratamiento con KNO3 o AG3 incrementa la germinación de las semillas. La germinación se evaluó con un diseño completamente al azar con tres tratamientos (testigo y promotores de la germinación KNO3 0.2 % y AG3 500 mg/L), cuatro tratamientos para la prueba de viabilidad (testigo, 0.2, 0.5 y 1.0 % de tetrazolio) y seis repeticiones de cada tratamiento. La germinación se evaluó en 100 semillas y la viabilidad en 25. Los resultados entre y dentro de años se analizaron con ANDEVA y prueba de comparación múltiple de medias de Tukey. La proporción de semillas no germinadas se cuantificó junto con el número de plántulas normales y anormales, semillas con embrión viable o sin él, y con viabilidad baja o sin viabilidad. En promedio la muestra recolectada en 2012 tuvo 36 % de semillas con embrión viable, 7 con viabilidad baja, 24 % no viables y 33 % sin embrión. Este resultado fue significativamente diferente al de 2015, que presentó 87 % de embriones viables, 10 % con viabilidad baja, 0 % no viables y 3 % sin embrión. La germinación también fue significativamente diferente entre los años (22 y 92 %). Los tratamientos pregerminativos no modificaron la germinación. La germinación y la viabilidad de las semillas de H. perotensis varían significativamente entre los años de recolecta.

Abstract:Endemic populations of Hechtiaperotensis have been described in Puebla and Veracruz, Mexico. Good quality seed collections can be used in conservation, research and ecological restoration. To evaluate seed quality of wild and endemic species, some compounds are used as effective promoters of germination, such as potassium nitrate (KNO3) and gibberellic acid (AG3), because they increase seed germination capacity and reduce latency. The triphenyl tetrazolium chloride (tetrazolium) test correlates seed viability because it is based on the activity of dehydrogenases in live tissues that catalyze mitochondrial respiration. The objective of this study was to obtain information on size and weight of capsules and seeds and seed germination and viability of H.perotensis, collected in Veracruz in the year 2012 and 2015. The hypotheses were 1) that seed germination and viability are independent of the year of collection, 2) that there is a tetrazolium concentration that can identify seed viability better than others, and 3) that pretreatment with KNO3 or AG3 improves seed germination. Seed germination was assessed using a completely randomized design with three treatments (control and the germination promoters 0.2 % KNO3 and 500 mg/L AG3), four treatments for the viability test (control, 0.2, 0.5 and 1.0 % of tetrazolium) and six replicates for each treatment. A total of one hundred seeds for germination experiments, and 25 seeds for the viability test were used. The results between and within years were analyzed with ANOVA and multiple comparison with the Tukey test. The proportion of non-germinated seeds was quantified along with the number of normal and abnormal seedlings, seeds with viable embryo, seeds without embryo, and seeds with low or no viability. On average, for the 2012 collected sample, 36 % had viable embryos, 7 % had low viability, 24 % were not viable and 33 % had no embryo. This result was significantly different from the 2015 sample, for which 87 % of seed showed viable embryos, 10 % had low viability, 0 % was not viable and 3 % had no embryo. Seed germination was also significantly different between years (22 and 92 %) Pregerminative treatments did not improve germination. Seed germination and viability of H. perotensis significantly varied between years of seed collection. Rev. Biol. Trop. 65 (1): 153-165. Epub 2017 March 01.

Compatibilidade fenotípica entre cultivares de pereiras europeias eporta-enxertos de marmeleiro / Phenotypic compatibility among european pear cultivars and quince rootstocks

A cultura da pereira (Pyrus communisL.) possui grande potencial de expansão no sul do Brasil devido às condições climáticas e de solo. A carência de informações a respeito da(s) melhor(es) combinação(ões) de cultivares 'copa de pereiras europeias' e porta-enxertos de marmeleiro em relação à compatibilidade de enxertia é um dos fatores que tem limitado o cultivo de pera no país. A utilização de porta-enxertos de marmeleiros apresentam as vantagens de redução do vigor e rápida entrada em produção, porém, quando enxertados com algumas cultivares de 'pereira europeia', pode acarretar incompatibilidade de enxertia. O trabalho foi realizado com o objetivo de avaliar fenotipicamente a compatibilidade morfológica entre cultivares 'copa de pereiras europeias' e porta-enxertos de marmeleiro através das variáveis de crescimento das plantas, como o incremento de diâmetro (mm) do tronco da cultivar e do porta-enxerto; diferença de diâmetro entre a cultivar e o porta-enxerto; incompatibilidade 'translocada'; incompatibilidade 'localizada'; e análise da conexão vascular no ponto de enxertia pela imersão em solução corante de Ácido Fuccínico 0,08%. Os experimentos foram conduzidos em pomares de pereiras europeias na região de Urupema, estado de Santa Catarina, durante os ciclos de cultivo 2011/12, 2012/13 e 2013/14. As combinações de cultivares de pereiras europeias e porta-enxertos avaliados foram a 'Abbè Fetel'/'Adams', 'Decana du Comice'/'Adams', 'Clapp's Favourite'/'EMA', 'Rocha'/'Adams', 'Packham´s Triumph'/'EMA' e 'Santa Maria'/'Adams'. A combinação 'Clapp´s Favourite'/'EMA' apresentou incompatibilidade do tipo 'localizada' pela descontinuidade vascular na região de união do enxerto, impedindo a passagem do corante. As combinações 'Rocha'/'Adams' e 'Abbè Fetel'/'Adams' não apresentaram incompatibilidade de enxertia. Nessas combinações, foram observadas união vascular contínua entre as cultivares e os porta-enxertos. As combinações ...

The pear (Pyrus communis L.) crop offers an expansive market opportunity in southern Brazil, because of amicable climatic and soil conditions. However, the lack of studies on compatibility of european pear cultivars and rootstocks is one of the limiting factors on the development of the pear crop in southern Brazil. The use of quinces as rootstocks has the advantages of vigor reduction and earlier bearing trees. However, some of these combinations can present some incompatibility graft. The objective of this study was to evaluate phenotypicaly the morphological compatibility among european pear cultivars and quince rootstocks. The evaluated variable were the section increment of cultivars and rootstocks trunk diameter at the graft union; the diameter difference between scion and cultivars and rootstocks; 'translocated' incompatibility; 'located' incompatibility; and the vascular connection of the graft union by immersion of the base of the plants (under the graft union) in a 0.08% Fuccinic acid solution. The experiments were conducted in an european pear orchards in the region of Urupema municipality, state of Santa Catarina, during the 2011/12, 2012/13 and 2013/14 growing seasons. The european pear cultivars and rootstocks evaluated were: 'Abbé Fetel'/'Adams', 'Decana du Comice'/'Adams', 'Clapp's Favourite'/'EMA', 'Rock'/'Adams', 'Packham's Triumph'/'EMA' and 'Santa Maria'/'Adams'. 'The Clapp´s Favourite'/'EMA' combination showed a `located incompatibility by descontinued vascular graft region, preventing the dye translocation. 'The Rocha'/'Adams' and 'Abbè Fetel'/'Adams' combinations did not present graft incompatibility, showing continued vascular union and no vascular disruption between cultivars and rootstocks. The 'Santa Maria'/'Adams', 'Decana du Comice'/'Adams' and 'Packham´s Triumph'/'EMA' combinations showed a good graft union region with clear and continued bark and wood bond lines. The 'Clapp´s Favourite'/'EMA' ...

Physiological and phytosanitary potential of rocket seeds / Potencial fisiológico e fitossanitário de sementes de rúcula

The objective of this study was to evaluate the physiological and sanitary quality of seeds of rocket; the research was done at the Laboratory of Seed Analysis and greenhouse of the Department of Plant Science, Federal University of Pelotas (UFPel). Four lots of the cultivar "Antonella'' were tested for following features: initial and final moisture content, germination rate, first count of germination, accelerated aging with saline solution, dry matter contents, seedling shoot and root length, emergence speed index, emergence of seedlings in substrate, electrical conductivity and sanitary condition. A completely randomized design with four replications was used for all tests done and means were compared by Tukey test (P≤0.05). For all tests performed it was concluded that despite changes in the ranking of the best lots, there was agreement regarding the indication of the inferiority of the lot 3 in all tests and it was also observed that the incidence of fungi associated with seeds of rocket interfere with the physiological quality of the lots.

O objetivo nesta pesquisa foi avaliar a qualidade fisiológica e sanitária de sementes de rúcula. O trabalho foi conduzido no laboratório e em casa de vegetação do Departamento de Fitotecniada Universidade Federal de Pelotas (UFPel). No ensaio, foram utilizados quatro lotes de sementes de rúcula da cultivar 'Antonella', sendo efetuados os seguintes testes: grau de umidade inicial e após o envelhecimento acelerado, germinação, primeira contagem de germinação, envelhecimento acelerado com solução salina, massa seca da parte aérea e de raiz de plântulas, comprimento da parte aérea e de raízes de plântulas, índice de velocidade de emergência, emergência de plântulas, condutividade elétrica e teste de sanidade, em delineamento experimental inteiramente casualizado, com quatro repetições, sendo que as médias foram comparadas pelo teste de Tukey (P≤0,05). Apesar das alterações na classificação dos melhores lotes, nos testes analisados, verificou-se concordância quanto à indicação da inferioridade do lote 3 em todas as avaliações. Verificou-se que a incidência dos fungos associados às sementes de rúcula interfere na qualidade fisiológica dos lotes.

Superação da dormência tegumentar de sementes de Piptadenia viridiflora (Kunth) Benth pela escarificação química / Overcoming tegumentary seed dormancy Piptadenia viridiflora (Kunth) Benth by chemical scarification

O objetivo deste trabalho foi avaliar os efeitos de diferentes períodos de imersão de sementes de Piptadenia viridiflora (Kunth) em ácido sulfúrico visando a maximização de valores de germinação, emergência e vigor de plântulas. Para o ensaio conduzido em laboratório, foi definido o delineamento inteiramente casualizado, com quatro repetições, sendo a parcela experimental constituída por uma placa de Petri, contendo 50 sementes, totalizando 200 sementes por tratamento. As placas de Petri foram mantidas em câmara BOD a temperatura de 25 ºC, com fotoperíodo de oito horas. Para avaliação em casa de vegetação foi instalado um ensaio com delineamento em blocos casualizados, com quatro repetições, sendo a parcela experimental constituída de 50 sementes distribuídas em fileira, totalizando 200 sementes por tratamento. Avaliou-se o efeito de períodos de imersão (15, 30, 45, 60 minutos) das sementes, em ácido sulfúrico (98 %), na germinação, IVG (Índice de Velocidade de Germinação), emergência, IVE (Índice de Velocidade de Emergência) e vigor das sementes (comprimento do caule, peso da massa fresca da raiz e parte aérea, peso da massa seca da parte aérea, peso de massa fresca total) e índice Spad. A escarificação química por exposição ao ácido sulfúrico concentrado foi eficiente para superação da dormência dessa espécie, promovendo elevação da porcentagem de todos os parâmetros avaliados. A maximização de valores foi verificada para o período de imersão entre 23 e 38 minutos de exposição à escarificação química.

The aim of this work was to evaluate the best immersion time in sulfuric acid to maximize germination, emergence and vigor values of seedlings. It was evaluated immersion time (15, 30, 45, 60 min) in sulfuric acid (98%) to seed germination, emergency, IVG (germination speed index), IVE (emergence speed index), seed vigor (stem length, fresh mass weight of roots and shoots, dry mass weight of shoots, total fresh mass weight) and Spad index. The laboratory trial was defined by completely randomized design with four replicates, and the plot consists of a Petri dish (145 mm diameter) containing 50 seeds, totalizing 200 seeds per treatment. Petri dishes were kept in BOD incubator at 25°C with a photoperiod of eight hours. For evaluation of emergency, it was conducted an experiment with a randomized block design with four blocks, and the plot consisted of 50 seeds. The sulfuric acid was efficient in overcoming the dormancy of the species, increasing the percentage of all characteristics evaluated. The efficiency of chemical treatment with concentrated sulfuric acid depends on the immersion time, and the period between 23 and 38 min is most suitable to provide higher percentages of germination and emergence.

Emergência de plântulas de Bauhinia divaricata L. em diferentes posições e profundidades de semeadura / Seedling emergence of Bauhinia divaricata L. at different sowing positions and depths

Bauhinia divaricata L. é uma espécie arbórea amplamente distribuída no Brasil, de alto valor ornamental e econômico, se propaga por meio de sementes, mas a germinação tem sido pouco pesquisada. Dessa forma, no presente trabalho o objetivo foi verificar o efeito da posição e profundidade de semeadura sobre a emergência e o desenvolvimento inicial de plântulas de B. divaricata. O delineamento experimental foi inteiramente ao acaso, com os tratamentos distribuídos em esquema fatorial 3 x 6 (posições e profundidades de semeadura), sendo as posições de semeadura constituídas por semente com o hilo voltado para baixo (HB), para cima (HC) e para o lado (HL) nas profundidades de um, dois, três, quatro, cinco e seis centímetros. Na avaliação do efeito dos tratamentos determinou-se a emergência, primeira contagem (PC), índice de velocidade de emergência (IVE), comprimento e massa seca da parte aérea e das raízes de plântulas. As posições de semeadura não interferem na emergência das plântulas de Bauhinia divaricata, sendo a profundidade de 1,64 cm a mais indicada para promover maior emergência e crescimento inicial das plântulas.

Bauhinia divaricata L. is a tree widely distributed in Brazil, with high ornamental value and cost. Its propagation is by seeds, which have been little investigated. Thus, this study aimed to investigate the effect of position and depth of the seed at sowing on the process of emergence and seedling vigor of the Bauhinia divaricata L. The experimental design was completely randomized with treatments arranged in a factorial 3 x 6 (positions and sowing depths), and the positions established by sowing seed with the hilum facing downwards (HB), up (HC) and to the side (HL) at depths of one, two, three, four, five and six centimeters. In evaluating the effect of treatment was determined to emergency first count (PC), emergence rate index (IVE), length and dry mass of shoots and roots of seedlings. The positions do not interfere with seeding seedling emergence of Bauhinia divaricata, and the depth of 1.64 cm more indicated to promote greater emergence and early growth of seedlings.