Sorghum hybrids grown in hydroponics contrast for phosphorus use efficiency / Híbridos de sorgo crescidos em hidroponia contrastam para eficiência de uso de fósforo

Phosphorus (P) use efficiency is crucial for sorghum production. P acquisition efficiency is the most important component of P use efficiency. The early-stage evaluation of plant development is a useful tool for identifying P-efficient genotypes. This study aimed to identify sorghum hybrids that are efficient in P use efficiency and assess the genetic diversity among hybrids based on traits related to P acquisition efficiency. Thus, 38 sorghum hybrids and two inbred lines (checks) were evaluated under low and high P in a paper pouch system with nutrient solution. Biomass and root traits related to P efficiency were measured. There was no interaction between genotypes and P levels concerning all evaluated traits. The biomass and root traits, except root diameter, presented smaller means under low P than high P. Efficient and inefficient hybrids under each P level were identified. The genetic diversity assessment grouped these genotypes in different clusters. The hybrids AG1090, MSK326, AG1060, 1G100, AS 4639, DKB 540, and DKB 590 were superior under low-P and high-P. Hybrids SC121, 1236020 e 1167017 presented the lowest means than all other hybrids, under both conditions. The evaluated hybrids showed phenotypic diversity for traits related to P acquisition, such as root length and root surface area, which can be useful for establishing selection strategies for sorghum breeding programs and increasing P use efficiency.

A eficiência do uso do fósforo (P) é fundamental para a produção de sorgo. A avaliação no estágio inicial do desenvolvimento da planta é uma ferramenta útil para a identificação de genótipos eficientes de P. Este trabalho teve como objetivo identificar híbridos de sorgo que sejam eficientes ao uso de P e avaliar a diversidade genética entre os híbridos com base em características relacionadas à eficiência de aquisição de P. Assim, 38 híbridos de sorgo e duas linhagens (testemunhas) foram avaliados sob baixo e alto P em sistema de pastas de papel com solução nutritiva. Características de biomassa e de raiz relacionadas à eficiência de P foram mensuradas. Não houve interação entre genótipos e níveis de P em todas as características avaliadas. As características de biomassa e raiz, exceto o diâmetro da raiz, apresentaram médias menores sob baixo P em comparação com alto P. Híbridos eficientes e ineficientes sob cada nível de P foram identificados e agrupados quanto à diversidade genética. Os híbridos AG1090, MSK326, AG1060, 1G100, AS 4639, DKB 540 e DKB 590 foram superiores sob baixo-P e alto-P. Os híbridos SC121, 1236020 e 1167017 apresentaram as menores médias que todos os outros híbridos, em ambas condições. Os híbridos avaliados apresentaram diversidade fenotípica para características relacionadas à aquisição de P, como comprimento e área superficial da raiz, o que pode ser útil para estabelecer estratégias de seleção para programas de melhoramento de sorgo e aumentar a eficiência de uso do P.

Aqueous plant extracts in the control of Bidens pilosa L / Extratos aquosos vegetais no controle de Bidens pilosa L

Secondary compounds have allelopathic action on germination and growth, and initial development of seedlings and beggar tick can have its germination and growth affected by the action of allelopathic extracts. Thus, this work aimed to evaluate the allelopathic potential of Brachiaria (Brachiaria brizantha), sunflower (Helianthus annuus) and sorghum extracts (Sorghum bicolor) on germination and initial growth of beggar ticks (Bidens pilosa). For this, an experiment was conducted in a completely randomized design with four treatments and six replicates and brachiaria, sunflower and sorghum extracts and control (distilled water) treatments. Extracts were obtained using 200 g of plant material and 1,000 mL of distilled water. Seeds were distributed in gerbox containing two sheets of germitest paper moistened with treatments and taken to germination chamber. Germination was daily monitored, and ten days after, initial growth was evaluated. Extracts did not reduce germination. However, they caused increase in germination time, mainly by brachiaria extract. Seedlings submitted to brachiaria and sorghum extracts showed lower growth. Brachiaria and sorghum extracts showed no action on germination, but controlled the initial growth of beggar tick, being potential natural herbicides.(AU)

Compostos secundários têm ação alelopática sobre a germinação, crescimento e desenvolvimento inicial de plântulas, e a Bidens pilosa pode ter sua germinação e crescimento afetados pela ação dos extratos alelopáticos. Nesse sentido, objetivou-se avaliar o potencial alelopático de extratos de braquiária (Brachiaria brizantha), girassol (Helianthus annus) e sorgo (Sorghum bicolor) na germinabilidade e no crescimento inicial de picão-preto (Bidens pilosa). Para isso foi instalado um experimento no delineamento inteiramente casualizado, com quatro tratamentos e seis repetições, sendo eles extrato de braquiária, girassol, sorgo e o controle (água destilada). Os extratos foram obtidos utilizando 200 g de material vegetal fresco para 1.000 mL de água destilada. As sementes foram distribuídas em caixa gerbox contendo duas folhas de papel germitest umedecidas com os tratamentos e levadas para a câmara de germinação. Foi acompanhada diariamente a germinação e, após 10 dias, foi avaliado o crescimento inicial. Os extratos não causaram prejuízos à germinação, porém, provocaram demora em seu tempo de eclosão, sendo o extrato de braquiária o mais prejudicial. As plântulas submetidas aos extratos de braquiária e sorgo apresentaram menor crescimento. Os extratos de braquiária e sorgo não apresentaram ação sobre a porcentagem de germinação das sementes de picão-preto, mas controlaram o crescimento inicial das plântulas e podem ser indicados para possíveis herbicidas naturais.(AU)

Evaluation of fitness in F2 generations of Africa Biofortified Sorghum event 188 and weedy Sorghum bicolor ssp. drummondii

Background: Introgression of transgenes from crops to their wild species may enhance the adaptive advantage and therefore the invasiveness of and weedy forms. The study evaluated the effect of Africa Biofortified Sorghum (ABS) genes from ABS event 188 on the vegetative and reproductive features of the F2 populations derived from crosses with Sorghum bicolor subsp. drummondii. Results: F1 populations were obtained from reciprocal crosses involving ABS event 188 and its null segregant with inbred weedy parents from S. bicolor subsp. drummondii. Four F2 populations and four parental populations were raised in RCBD with 4 replications in a confined field plot for two seasons. Vegetative and reproductive traits were evaluated. The vigour shown in the F2 populations from the reciprocal crosses involving ABS event 188 and S. bicolor subsp. drummondii was similar to that in the crosses involving the null segregant and S. bicolor subsp. drummondii. Differences in vegetative and reproductive parameters were observed between the parental controls and the F2 populations. Examination of the above and below ground vegetative biomass showed lack of novel weedy related features like rhizomes. Conclusions: Therefore, release of crops with ABS 188 transgenes into cropping systems is not likely to pose a risk of conferring additional adaptive advantage in the introgressing populations. The interaction of ABS genes in weedy backgrounds will also not have an effect towards enhancing the weedy features in these populations.

Energy partitioning and methane emission by sheep fed sorghum silages at different maturation stages / Partição de energia e emissão de metano por ovinos alimentados com silagem de sorgo em diferentes estádios de maturação

Energy partitioning and methane production by sheep fed silages of three commercially available sorghum hybrids (BRS 610, BR 700 and BRS 655) harvested at three maturation stages (milk, soft dough and floury) were evaluated in open circuit respiration chambers. A complete randomized design was used in a 3 × 3 (hybrids × maturity stages) factorial arrangement, and the means were compared by the Student-Newman-Keuls (SNK) test (P<0.05). The intake of dry matter, digestible dry matter, gross energy, digestible energy and metabolizable energy were not affected by maturation stage, but were influenced by hybrid. The net energy intake was influenced by maturity and sorghum genetics. The fecal output represented the main source of energy loss, as percentage of gross energy intake (48% to 52%), followed by heat increment (10% to 19%), methane emissions (4% to 6%) and urine (1% to 2%). There were no differences (P>0.10) among the treatments for the apparent digestibility of gross energy and metabolizability (qm). An interaction (P<0.05) between sorghum hybrid and maturation stages was observed for the efficiency of metabolizable energy utilization for maintenance (km), which ranged between 0.53 and 0.78. No differences (P>0.10) among treatments occurred in the daily methane production. There is substantial genetic diversity within sorghum species, determining different nutritional values. Sorghum genetics and maturity at harvest should not be an opportunity to reduce the contribution of agriculture to methane emissions.

A partição de energia e a produção de metano por ovinos alimentados com silagens de três híbridos de sorgo comerciais (BRS 610, BR 700 e BRS 655), colhidos em três estádios de maturação (leitoso, pastoso e farináceo), foram avaliadas em câmaras respirométricas de circuito aberto. Utilizou-se delineamento inteiramente ao acaso, em arranjo fatorial 3 x 3 (híbridos x estádios de maturação), e as médias foram comparadas pelo teste Student-Newman-Keuls (SNK) (P<0,05). Os consumos de matéria seca, de matéria seca digestível, de energia bruta, de energia digestível e de energia metabolizável não foram afetados pelo estádio de maturação, mas foram influenciados pelo híbrido de sorgo. O consumo de energia líquida foi influenciado pela maturidade e pelo híbrido. As perdas de energia nas fezes representaram a principal fonte de perda energética como porcentagem do consumo de energia bruta (48% a 52%), seguida pelo incremento calórico (10% a 19%), pela emissão de metano (4% a 6%) e pela urina (1 a 2%). Não houve diferenças (P>0,10) entre os tratamentos para a digestibilidade aparente da energia bruta e para a metabolizabilidade (qm). Foi observada interação (P<0,05) entre híbrido de sorgo e estádio de maturação para eficiência de uso da energia metabolizável para mantença (Km), que variou entre 0,53 e 0,78. Não ocorreram diferenças (P>0,10) entre tratamentos na produção diária de metano. A emissão de metano em gramas por kg de matéria seca digestível e por kg de fibra em detergente neutro digestível foi inferior no estádio pastoso comparado ao estádio farináceo.

Intoxicação espontânea por Sorghum sudanense em bovinos leiteiros no Rio Grande do Sul / Spontaneous poisoning by Sorghum sudanense in dairy cattle in Rio Grande do Sul

Descreve-se um surto de intoxicação espontânea por Sorghum sudanense (aveia de verão, capim-sudão) em um rebanho de bovinos leiteiros no município de Triunfo, Rio Grande do Sul. Essa planta é utilizada como forrageira em diversas regiões do estado; entretanto, intoxicações ocasionais são associadas com a formação de ácido cianídrico por hidrólise dos glicosídeos cianogênicos presentes na planta. Vinte e nove vacas Holandesas foram colocadas, no final do dia, em um potreiro de 800m², onde uma pastagem estabelecida de capim-sudão rebrotava e atingia 30cm de altura. Na manhã seguinte, quase todo pasto havia sido consumido e três vacas foram encontradas mortas. Não foram relatados sinais clínicos, mesmo porque os animais não foram observados durante a noite. Exceto pela presença de folhas mastigadas de capim-sudão nas proximidades da entrada do rúmen, não foram observadas alterações macro ou microssópicas. Amostras da planta de diferentes locais no potreiro foram positivas no teste do papel picrossódico. Esses achados sugerem que as três vacas foram afetadas por intoxicação cianídrica secundária ao consumo de Sorghum sudanense.

An outbreak of Sorghum sudanense (Sudan grass) poisoning affected three cows from a dairy herd in Triunfo, Rio Grande do Sul, Brazil. Although S. sudanense has been used as a source of forage for cattle, sporadic poisoning occurs in association with management failures of these pastures. Cyanogenic glycosides present in the plant may form hydrogen cyanide through hydrolysis and may cause livestock poisoning. Twenty-nine Holstein cattle were allowed to graze in an 800m² paddock, in which lush sprouts of sudanense were 30cm high. Animals were placed on pasture at evening and, in the next morning, most forage had been consumed and three cattle were found dead. No clinical disease was noticed. Except by the presence of chewed sudan grass leaves near to the entrance of the rumen, there were neither macroscopic nor microscopic changes, Samples of S. sudanense taken from different places in the paddock were positive when evaluated by the picrosodic paper test. Such findings suggested that those three cows were affected by cyanide poisoning secondary to Sorghum sudanense consumption.

Efeito alelopático de folhas de bamburral [Hyptis suaveolens (L. ) Poit] sobre a germinação de sementes de sorgo (Sorghum vulgare Pers. ), rabanete (Raphanus sativus L. ) e alface (Lactuca sativa L. ) / Allelopathic effects of leaves of "bamburral" [Hyptis suaveolens (L. ) Poit] on the germination of seeds of sorghum (Sorghum vulgare Pers. ), radish (Raphanus sativus L. ) and lettuce (Lactuca sativa L. )

O objetivo do presente trabalho foi à verificação do efeito alelopático de Hyptis. suaveolens na germinação de sorgo, alface e rabanete, bem como, a comprovação da existência de compostos com potencial alelopático. Sementes de sorgo, alface e rabanete foram semeadas em substrato constituído de areia, terra e adubo orgânico contendo folhas de H. suaveolens. As análises da germinação foram feitas considerando a protrusão da radícula para o término do evento germinativo. Foi calculado o IVG (índice de velocidade de germinação) e %G (porcentagem de germinação). Os resultados mostraram que sorgo e a alface foram mais susceptíveis ao potencial alelopático de H. suaveolens, sendo que para o rabanete foi observado um efeito benéfico. Entre os tratamentos, o substrato esterilizado e não esterilizado mostraram diferenças entre si. A análise cromatográfica do óleo essencial presente nas folhas de H. suaveolens revelou a presença de compostos com potencial alelopático. Portanto, H. suaveolens, pode apresentar efeito alelopático positivo no IVG de sementes de rabanete e a presença de microorganismos pode ser necessária para que esse efeito alelopático aconteça.

The aim of this study was to verify the allelopathic effect of H. suaveolens on the germination of sorghum, lettuce and radish, as well as to prove the existence of compounds with allelopathic potential. Seeds of sorghum, lettuce and radish were sown in substrate consisting of sand, soil and organic fertilizer containing leaves of H. suaveolens. The germination tests were performed considering the protrusion of the radicle for the conclusion of the germinative event. GSI (germination speed index) and G% (percentage of germination) were calculated. The results showed that sorghum and lettuce were more susceptible to the allelopathic potential of H. suaveolens, while for radishes a beneficial effect was observed. Between treatments, the sterilized and unsterilized substrate showed differences. The chromatographic analysis of essential oil present in the leaves of H. suaveolens revealed the presence of compounds with allelopathic potential. Therefore, H. suaveolens may have positive allelopathic effect on the GSI of radish seeds, and the presence of microorganisms may be necessary for such an allelopathic effect to occur.

Evaluación agronómica de genotipos de sorgo y millo (Sorghum vulgare) forrajeros para alimentación de bovinos en el medio Sinú / Agronomic evaluation of forages sorghum (Sorghum vulgare) and millo genotypes for feeding bovine in the Sinú valley

Objetivo. Evaluar siete genotipos de millo y cinco genotipos de sorgo, para determinar el rendimiento forrajero y su utilidad en la alimentación de bovinos en el valle del medio Sinu. Materiales y métodos. Las semillas de sorgo y millo (Sorghum vulgare), fueron materiales híbridos y variedades tipo comercial. Se utilizó un diseño de bloques completos al azar con 4 cuatro repeticiones para millo y tres para sorgo. Resultados. Respecto al vigor los genotipos de millo que mejor comportamiento presentaron fueron el redondo cuba y blanco panoja larga; en sorgo el LC 603, el P-8239 y el DR-1125. Los millos que mostraron mayor senescencia fueron el cuarentano alto, el bastón y el blanco panoja larga; en sorgo los de mayor senescencia fueron el P-8239, el LC 603 y el 74 CO. La mayor producción de forraje verde y materia seca la presentaron los genotipos de millo, el batea cuba, el redondo cuba y el blanco panoja larga, los de sorgo fueron el blanco criollo y el DR-1125. El mayor rendimiento de grano fue de los genotipos el batea cuba y bastón en millo, y en sorgo fueron DR-1125 y LC 603. Se seleccionaron como materiales de buen comportamiento dentro de todos los evaluados el batea cuba, redondo cuba, y blanco panoja larga en millo y el blanco criollo y DR-1125 en sorgo. Conclusiones. Los genotipos de millo que mejor comportamiento presentaron fueron en su orden por rendimiento (ton/ha): el batea cuba, el redondo cuba y el blanco panoja larga (ton/ha), obteniéndose una mayor capacidad de carga animal. Los genotipos de mejor comportamiento de sorgo fueron el blanco criollo y el DR-1125.

Inter-relationship between growth analysis and carbohydrate contents of sweet sorghum cultivars and lines.

The carbohydrate contents of sweet sorghum (Sorghum bicolor L. Moench) is an important industrial factor for crystal sugar or bioethanol production. In this study the relationship between growth analysis and carbohydrate contents were studied to recognize the best growth stages for sweet sorghum harvesting. Five sweet sorghum cultivars and four sweet sorghum lines were evaluated for leaf area index (LAI), net assimilation rate (NAR), relative growth rate (RGR) and stem crop growth rate (CGR) in relation to sucrose content, invert sugars and total sugar at booting, soft-dough, hard dough and post grain maturity Except at post grain maturitystage, the correlations among LAI, NAR and RGR forsucrose content and total sugar were positive and forinvert sugars were negative. The relationship between invert sugars including glucose, fructose, maltose and xylose athard dough stage regarding LAI, NAR and GRG were negative. As plant grows LAI, NAR and RGR increases which consequently increases sucroses content and decrease invert sugar.

Effects of irrigation water qualities on biomass and sugar contents of sugar beet and sweet sorghum cultivars.

An experiment involving four qualities of irrigation water two sugar beet and three sweet sorghum cultivars was conducted in a split plot design with four replications at Rudasht Drainage and Reclamation Experiment Station in 1999. The results showed salinity of water has an adverse effect on sugar beet and sweet sorghum biomass. Sweet sorghum cultivar SSV108 had the lowest biomass under all qualities of irrigation water Sweet sorghum cultivar Rio had the maximum biomass with water qualities of 2, 5, and 8 dS m(-1). Sugar beet cultivar 7233 had the maximum biomass with 11 dS m(-1). The effect of irrigation water quality was not significant for sugar characteristics such as brix, pol and purity. However, responses of cultivars on the above parameters were significant and sugar beet cultivars had higher brix, pol and purity and lower invert sugar and starch than sweet sorghum cultivars. In conclusion, sweet sorghum cultivars are not recommended to be irrigated with saline water of more than 8 dS m(-1) for sugar production. Under such condition, they may be suitable to be grown for forage purposes.

Effect of water quality on yield of sugar beet and sweet sorghum.

To study the effects of quality of water on soil and plant, an experiment was conducted at Rudashat Drainage and Reclamation Experiment Station in 1999. Four irrigation water salinities (2, 5, 8 and 11 ds m(-1)) and two sugar crops (sugar beet and sweet sorghum) were used in this experiment. The results showed that under the same water quality, sweet sorghum used 2700 cubic meter per hectare less water than sugar beet. As the quality of irrigation water decreased, the soil salinity and exchangeable sodium percent increased which caused yield reduction for both plants. Sugar beet by accumulating Na and Cl in its leaves tolerated salinity but its usage as a forage crop caused some limitations, whereas sweet sorghum by not accumulating Na and Cl escape salinity and it can be used as a forage crop without any limitation.

Efficient regeneration of sorghum, Sorghum bicolor (L.) Moench, from shoot-tip explant.

Novel protocols for production of multiple shoot-tip clumps and somatic embryos of Sorghum bicolor (L.) Moench were developed with long-term goal of crop improvement through genetic transformation. Multiple shoot-tip clumps were developed in vitro from shoot-tip explant of one-week old seedling, cultured on MS medium containing only BA (0.5, 1 or 2 mg/l) or both BA (1 or 2 mg/l) and 2,4-D (0.5 mg/l) with bi-weekly subculture. Somatic embryos were directly produced on the enlarged dome shaped growing structures that developed from the shoot-tips of one-week old seedling explants (without any callus formation) when cultured on MS medium supplemented with both 2,4-D (0.5 mg/l) and BA (0.5 mg/l). However, the supplementation of MS medium with only 2,4-D (0.5 mg/l) induced compact callus without any plantlet regeneration. Each multiple shoot-clump was capable of regenerating more than 80 shoots via an intensive differentiation of both axillary and adventitious shoot buds, the somatic embryos were capable of 90% germination, plant conversion and regeneration. The regenerated shoots could be efficiently rooted on MS medium containing indole-3-butyric acid (IBA 1 mg/l). The plants were successfully transplanted to glasshouse and grown to maturity with a survival rate of 98%. Morphogenetic response of the explants was found to be genotypically independent.