ABSTRACT
This investigation was conducted to study combining ability along with inheritance of grain yield and its component traits in 36 hybrids of pearl millet which were generated through line × tester mating design using 12 male sterile lines and 3 restorers as parental material at IIMR, Hyderabad during kharif, 2022. These hybrids were evaluated in randomized block design with 3 replications during kharif, 2022 and summer, 2023 at IIMR, Hyderabad. In results, both GCA and SCA variances were found significant for majority of characters. The ratio of GCA and SCA variance indicated the predominance of non-additive gene action for all the characters studied except for panicle length and panicle width. GCA effects revealed that parents like 274A, 269A, 04999A and 260A (female) and 123R (male) were good general combiners for grain yield and some contributing characters. On the basis of SCA effects the crosses namely 252A × 124R, 843-22A × 124R, 843-22A × 132R, 242A × 123R, 264A × 132R and 274A × 123R were identified as superior for grain yield and related traits over the seasons. Therefore, it is advised that these parents and hybrids be used in the creation of fruitful hybrids as well as for population growth.
ABSTRACT
O cultivo do feijoeiro, Phaseolus vulgaris L., possui grande importância para o Brasil, sobretudo no âmbito econômico e social. Assim, a utilização de ecótipos de feijoeiro promissores associada à otimização dos recursos hídricos configura importante estratégia para a agricultura sustentável em regiões semiáridas. Objetivou-se com este trabalho avaliar o comportamento de ecótipos de feijoeiro cultivados na época das águas com irrigação suplementar. O experimento foi no campus Experimental de Ecofisiologia Vegetal da Universidade Estadual da Paraíba, situada na microrregião de Catolé do Rocha, PB. Utilizou-se o delineamento experimental em blocos casualizados em fatorial 3x4, sendo três ecótipos de feijoeiro (Eco1= G2227, Eco2= BRA 130583 CIAT G6490 e Eco3= BAT 477) e quatro lâminas de irrigação suplementar com 50; 75; 100 e 125% da evapotranspiração de referência (ETo), em três repetições. As variáveis analisadas foram: percentagem e índice de velocidade de emergência, comprimento da haste principal, taxa de crescimento relativo, número de vagens por planta, número de grãos por vagem, massa de 100 grãos, fitomassa da parte aérea e eficiência fotossintética. Os ecótipos de feijoeiro analisados divergem entre si quanto aos aspectos de germinação, crescimento, componentes da produção (NGV e FMA) e eficiência fotossintética. O ecótipo 1 apresenta melhor desempenho quanto aos componentes da produção observados nas condições de Semiárido.
The cultivation of common bean Phaseolus vulgaris L. has great importance for Brazil, especially in the economic and social sector. Thus, the use of promising bean ecotypes associated with optimization of water resources sets an important strategy for sustainable agriculture in semiarid regions. This study was developed in order to evaluate the behavior of common bean ecotypes grown in the rainy season with supplementary irrigation. The experiment was carried out at campus Experimental Plant Ecophysiology at the State University of Paraiba, located in the microregion of Catolé do Rocha - PB. A randomized block experimental design in factorial 3x4 was used, with three common bean ecotypes (Eco1 = G2227, Eco2 BRA = 130583 CIAT G6490 and Eco3 BAT = 477) and four levels of supplementary irrigation (50, 75, 100 and 125% of reference evapotranspiration, ETo) in three replications. The variables analyzed were: percentage and emergence speed index, main branch length, growth rate relative crop, number of pods per plant, number of grains per pod, weight of 100 grains, shoots dry matter and photosynthetic efficiency. The bean ecotypes analyzed were different in aspects of germination, growth, yield components (NVG e FMA) and photosynthetic efficiency. The ecotype 1 shows better performance on the yield components observed in the semiarid conditions.
Subject(s)
Crop Production , Phaseolus , Efficiency , Sustainable Agriculture , Agricultural IrrigationABSTRACT
Thirty-days old rice (Oryza sativa L. cv. Jyothi) plants grown under the greenhouse (150-200 µmol m-2 s-1) or shade (600-800 µmol m-2s-1) were exposed to 7 days of full sunlight and compared with plants grown under direct sunlight (1200-2200 µmol m-2s-1).Transfer of greenhouse and shade plants to full sunlight for a day resulted in a decline in their photosynthetic efficiency (Fv/Fm) and an increase in non-photochemical quenching (qN). The decline in Fv/Fm was much greater in transferred greenhouse plants (33%) as compared to transferred shade-plants (20%). Sun-plants did not show much variation in the Fv/Fm ratio (4%) from their predawn measurements (control). The sun-grown plants showed a higher pool of xanthophyll pigments (violaxanthin + antheraxanthin + zeaxanthin). Transfer of greenhouse and shade-plants to full sunlight resulted in an increase in lutein, Chl a/b ratio, antheraxanthin (A) and zeaxanthin (Z) content. Increase in A and Z was correlated with the increase in the qN. The increase in the A and Z content was due to increase in the activity of violaxanthin de-epoxidase. Greenhouse and shade plants on exposure to sunlight showed an increase in lipid peroxidation (LPO). Prolonged exposure of greenhouse and shade plants up to 7 days resulted in recovery of the Fv/Fm, an increase in Z and A and a decline in the LPO. The study demonstrated that rice plants grown at lower light intensities initially underwent photoinhibitory damage on exposure to full sunlight, but were able to acclimate to the high irradiance by dissipating the excess light through various mechanisms such as an increase in lutein, high Chl a/b ratio and xanthophyll cycle, suggesting use of energy dissipation as a mechanism of protection against high irradiance, but to different extent and to some extent by different processes. The study was unique, as plants were grown and photoinhibited under natural conditions rather than the artificial light, as was the case in most of the studies so far. Results showed better adaptation of high-light grown plants and suggested role for chl a/b ratio and lutein, in addition to xanthophylls cycle in shade plants. Low-light grown plants could also completely adapt to full level of sunlight within 3 days of the treatment and xanthophylls cycle (measured as V, A and Z) and activity of de-epoxidase seemed to be important in this adaptation.
Subject(s)
Chlorophyll/metabolism , Linear Energy Transfer , Lipid Peroxidation , Oryza , Oxidoreductases , Photosynthesis/chemistry , Photosynthesis/physiology , Xanthophylls/metabolismABSTRACT
Impact of effluents discharged in Ganga through various sources on chemical composition, energy transformation rate and level of heavy metals was studied at Kanpur and Varanasi. The effluents were found to be nil in oxygen with acidic in oxygen with acidic to neutral pH (6.8-7.0) and having very high values of free CO2 (40-68 mg l-1), alkalinity (300.0-412.0 mg l-1), conductance (1082.0-1824.0 μmhos), total dissolved solids (542.0-912.0 mg l-1), hardness (228.0-330.0 mg l-1), chloride (42.0-60.0 mg l-1), organic matter (8.4-18.2 mg l-1) and BOD load (98.0-248.0 mg l-1). The heavy metals Cu, Cr, Cd, Pb and Zn were also quite high in the effluents (48.6-78.4, 54.0-84.6, 9.8-12.4, 72.4-84.0 and 148.6-284.0 μg l-1 respectively). The discharged effluents induced severe reduction in oxygen (av. 0.82-3.4 mg l-1) and sharp increase in the level of free CO2 (av. 10.8-24.8 mg l-1), alkalinity (182.4-288.4 mg l-1), conductance (480.0- 628.0 mmhos), total dissolved solids (254.0-315.0 mg l-1), hardness (170.0-259.0 mg l-1), chloride (36.0-52.0 mg l-1), organic matter (4.8-6.8 mg l-1) and BOD load (36.4- 58.4 mg l-1) at the discharge point (OF zones) from their comparatively much lower values before discharge (AOF zone). The rate of energy transformation and photosynthetic efficiency also reduced considerably at the discharge point (av. 1060-2101 calm-2day-1 and 0.09-0.18%) from high values before discharged point (av. 4045-4733 calm-2day-1 and 0.34-0.42%). The level of Cu, Cr, Cd, Pb and Zn also showed higher values at the discharged point (20.4-38.0, 22.4-54.8, 5.2-7.8, 30.8-72.0 and 64.8-120.8 μg l-1 respectively). Considerable improvement was observed below the discharge (BOF zone). Comparison with earlier observation revealed that the magnitude of impact has reduced considerably after the regulation in the discharge both in he respect of chemical composition and energy transformation rates.
ABSTRACT
Objective To select suitable vegetable for use in Controlled Ecological Life Support System for future long-term space missions. Method Five crops of lettuce(four Lactuca sativa L. var.crispa L.and one Lactuca sativa L. var.longifolia Lam), two crops of spinach(Spinacia oleracea L.), one rape(B.napus L.)and one common sowthisthe (Sonchus Oleraceus L.)were grown in a Controlled Ecological Life Support Technique Experimental System. Hydroponic nutrient solution, light, temperature and relative humidity were regulated, CO_2 levels were controlled at 500, 1 000, 1500 and 2 000 ?mol/mol, and light intensity were controlled at 100, 300, 500 and 700 ?mol/(m2?s). Canopy photosynthetic rate, transpiration rate and leaf aera were measured on day after planted (DAP) 25 and 30. Plants were harvested at maturity, and analyzed for total fresh weigh and proximate composition (crude fiber,nitrite and ?-carotene). Result Three crops of lettuce “nenlvnaiyou”, “dasusheng”,“youmaicai” ,and one common sowthisthe were selected. The favorite CO_2 concentration and light intensity 2 000 ?mol/mol, and 700 ?mol/(m2?s) respectively.Conclusion The four crops selected have high productivity, photosynthetic rates and transpiration rates, which can be considered as the basis of the vegetables to be used for future long-term space missions.