Evaluation of Soybean (Glycine max L.) Genotypes on the Basis of Biochemical Contents and Anti-oxidant Enzyme Activities

Background: Soybean is an important leguminous crop. Abnormal weather has played an enormous role in the strident decline in crop yields. Drought is considered as a significant abiotic factor responsible for yield reduction in soybean. Methods: The present work was carried out in order to screen soybean genotypes for their drought tolerance ability by means of different biochemical and antioxidant enzymatic activities responses. Conclusion: On the basis of biochemical parameters and anti-oxidant enzymatic activities, soybean genotype viz., RVS-211-77, RVS-211-75, NRC-7, SL-96, NRC-136, AMS100-39, SL-96, RVS-2012-01, RVS-211-73 and JS97-52 have been identified with better performance and can be used as parents for further crop improvement programme to breed drought tolerant variety.

Multi-Environmental Evaluation of Protein Content and Yield Stability among Tropical Soybean Genotypes Using GGE Biplot Analysis

The yield and protein performance in a soybean genotype result from its interaction with the prevailing environmental conditions. This makes selecting the best genotypes under varied target production environments more complex. This study’s objectives were to determine protein content and protein stability of 30 elite soybean genotypes in major soybean-growing areas of Uganda, assess the yield performance and stability in soybeans and determine the relationship between the protein content and grain yield in soybeans. The genotypes were planted in a randomized complete block design of three replications for six seasons across eight locations in Uganda. Genotype and genotype-by-environment (GGE) biplot analyses classified the test locations into three mega-environments for soybean protein and grain yields. Genotype NII X GC 20.3 had the highest mean protein content of 43.0%, and BSPS 48A-9-2 and BSPS 48A-28 were superior for the mean grain yield (1207 kg ha−1). Bulindi was the most discriminating and representative test environment for soybean yield. A weak and negative correlation (r = −0.1**, d.f. = 29) was detected between the protein content (%) and yield (kg ha−1). The highest-yielding genotypes BSPS 48A-9-2, BSPS 48A-31, and Nam II × GC 44.2 are recommended for further evaluation under farmers’ production conditions for selection and release as new soybean varieties in Uganda.

Fatty Acid Composition, Antinutritional Factors, and Oligosaccharides Concentration of Hawaijar (An Ethnic Fermented Soyfood of India) As Affected by Genotype and Bacillus Subtilis Strain

Hawaijar is an ethnic fermented soy product from the North-East region of India. The information on the effect of soybean genotype and the Bacillus subtilis strain used for inoculation for preparing the product on the fatty acid composition, the level of antinutritional factors, such as Kunitz trypsin inhibitor (KTI) and Bowman-Birk inhibitor (BBI), and oligosaccharides is not available. In the present study, Hawaijar was prepared from two soybean genotypes using two different strains of Bacillus subtilis and investigated for the concentration of the above-mentioned biomolecules. The results showed the significant effect of genotype used on oleic, linoleic, and α-linolenic acid of the product. KTI and BBI were found absent in Hawaijar prepared from these two genotypes and two strains. Flatulence-inducing factors like raffinose and stachyose were found in very low concentration irrespective of genotype and strain. Retention of sweetness-imparting sucrose and maltose concentration in Hawaijar was genotype-dependent.

Pertumbuhan dan produksi beberapa mutan kedelai Kipas Merah generasi ke lima di kebun percobaan Lampahan Bener Meriah

The research objective was to determine the growth and production of the fifth generation mutant soybean (M5) at the Lampahan Bener Meriah University Farm. This study used a non-factorial randomized block design (RBD) with three replications, where four genotypes of Kipas Merah mutants were tested and compared with Kipas Merah (their parents) and Grobogan variety (large seeds). The variables observed were plant height, number of branches, number of productive branches, days of flowering, number of pods, number of pithy pods, number of seeds, weight of seeds per plant and weight of 100 seeds. The results of this study indicate that the M5 mutant soybean genotype has no significant different on plant height at age 4, 6, 8 WAP, number of branches per plant aged 6, 8 WAP, number of pods, and number of productive branches per plant. The highest average plant height and the highest number of productive branches found in Kipas Merah (G0) varieties. Mutant soybean genotype M5 had a very significant effect on flowering age and seed weight per plot. The fastest flowering was Kipas Merah (G0) and the latest flowering was A11 (G4) and A14 (G5) mutants. The highest weight of 100 seeds found in mutant A11 (G4) about 18.585 g and no significant different with Grobogan variety (18.827 g). The highest seed weight per plot found in mutant A11 (G4) about 169.35g. Based on the results of this study, mutant A11 (G4) was the best growth and production of the tested M5 genotypes.

The use of detached leaf inoculation for selecting Cercospora kikuchii resistance in soybean genotypes

Cercospora leaf blight (CLB) causes extensive losses in soybean production in worldwide, including major soybean producing countries such as Argentina. C. kikuchii, C. cf. sigesbeckiae, C. cf. flagellaris, and C. cf. nicotianae are identified as pathogen of CLB. Soybean resistance for CLB is still unknown. Also, chemical control for CLB is losing effectiveness by fungicide resistance of the pathogen, such as C. kikuchii. We urgently need to breed a CLB resistant cultivar. Unfortunately, efficient methods for the screening of a resistant soybean genotype have not yet been established. In this study, we designed new, high-throughput inoculation method for identifying resistance against one of the CLB pathogen, C. kikuchii. We used liquid-cultured mycelia of the pathogen C. kikuchii on detached soybean leaves. Lesions on soybean leaflets appeared nine days post inoculation by this method. We used this method to select four C. kikuchii resistant genotypes from 80 genotypes in the World Soybean Core Collection. High-throughput screening method developed in this study can contribute to the research about C. kikuchii resistance by facilitating identification of resistant varieties.

Comparison of the Species Communities of Phytophthora, Pythium and Phytopythium Associated with Soybean Genotypes in High Disease Environments in Ohio

The role that specific cultivars with different levels and types of resistance may play on the diversity and abundance of Phytophthora, Phytopythium and Pythium species communities were compared. Three soybean cultivars were planted in a total of eleven different high disease environments in Ohio and seedlings were collected for direct isolation and amplicon sequencing of the rhizosphere soil. Plant population and yields were lower for the moderately susceptible cultivar Sloan compared to the cultivars Kottman, with high partial resistance to Ph. sojae, and Lorain with high partial resistance to both Pythium spp. and Ph. sojae. Based on both direct isolation and amplicon sequencing, distinct communities with key indicator species were identified at each environment, including differences at 14 and 25 day after planting for two environments. The environment had the largest influence on the community composition. Soybean genotype did influence the abundance of the hemibiotroph, Phytophthora sojae, but not species of Phytopythium or Pythium. In addition, from all environments and cultivars, OTU’s classified as Py. attrantheridium, Py. heterothallicum, and Py. sylvaticum were always detected. This is also the first report of an OTU of Py. periilum from soils and the first one to recover undescribed species that match the sequence of Pythium sp. CAL2011f from soybean seedlings in Ohio. This study highlights which species to target for the identification and development of resistant cultivars or for fungicide screening.

Seed longevity studies in wild type, cultivated and inter-specific recombination inbred lines (RILs) of soybean

Loss of seed viability is a serious hurdle in higher production and ambient seed storage of soybean. Understanding the factors affecting seed viability and identification of soybean genotype(s) with higher viability is critical for higher soybean production. In this study, seeds of 125 soybean genotypes of three different species (Glycine tomentella, Glycine soja and Glycine max) and 25 RILs (Glycine soja × Glycine soja) were tested for germination immediately after harvest followed by one, two and three years of ambient storage. Fresh seeds of all the genotypes recorded 78-99% germination with a mean of 94.02%. However, the mean value of per cent germination of all the genotypes after one, two and three years of ambient storage decreased and found to stand at 79.51%, 52.24% and 29.18%, respectively. Among the genotypes tested, G. tomentella accession registered highest seed storability followed by G. soja, RILs and G. max. After three years of storage, 14 wild type genotypes and 3 RILs maintained >70% germination and identified as ‘good storers’. Genetic divergence studies via k-mean clustering and principal component analysis grouped all genotypes in three cluster/component based on seed size, seed coat permeability and seed viability. Seed viability was significantly and negatively correlated with electrical conductivity. Good storers found to be having slow imbibition rate than poor storers in initial hours of imbibition. The good storing genotypes identified in this study will serve as an elite soybean genetic resource in developing the soybean cultivars with better seed longevity.

Response of soybean genotypes to iron limiting stress in calcareous vertisol under ambient and elevated CO2 and temperature conditions

Aim: To compare the relative performance of two contrasting genotypes of soybean to iron limiting conditions under ambient and elevated CO2 and temperature conditions. Methodology: A pot culture experiment was performed using calcareous vertisol soil. The environmental factors viz. CO2 and temperature were combined and applied as a single factor with two levels: a-[CO2+T] (400±10 µmol mol-1, day/night temperature 30oC/22oC) and e-[CO2+T] (610±10 µmol mol-1, day/night temperature 34oC/26oC). Soybean genotype that differed in iron use efficiency was used as another factor and two contrasting genotypes were used as two levels viz. iron efficient and responsive (FeER) and iron inefficient and responsive (FeIR). Results: The higher partial pressure of CO2 under elevated carbon dioxide and temperature condition (Pco2 = 61.8 Pa) dissolved the native CaCO3 from calcareous vertisol soil and thereby resulted in higher HCO3- ion concentration. The antagonistic interaction between Fe2+ with HCO3- ion resulted in greater iron stress. As compared to ambient condition, seed yield was significantly reduced under more stressed e-[CO2+T] condition and resulted in ~1.4 and ~1.9 times drop in FeER and FeIR genotypes, respectively. Iron efficient and responsive (FeER) genotype recorded an impressive performance, as compared to the iron inefficient and responsive (FeIR) genotype, in counteracting iron deficiency stress, both under ambient and elevated conditions. Interpretation: The intra-specific variability between soybean genotypes and their response to elevated CO2 and temperature can be exploited to remediate the emerging iron deficiency stress in soybean plants and suggest ways to structure the future breeding programmes to adapt to the climate change. Key words: Calcareous vertisol, Chlorosis, Climate change, CO2, Soybean