No abstract

Line × Tester combining ability analysis involving five lines (cultivars i.e., CIM-446, CIM-473, CIM-506, CIM-554 and SLH-284) and three testers (cultivars viz., CIM-496, CIM-499 and CIM-707) was carried out during 2015 and 2016 to determine the inheritance for earliness, yield and lint traits in upland cotton. Genotypes revealed significant (P≤0.01) variations for all the traits. On average, F 1 hybrids showed the significant increase over parental means for yield traits. Mean squares due to general (GCA) and specific combining ability (SCA) were highly significant, which suggested that additive and non-additive gene actions were involved in controlling all the characters. However, the preponderance of non-additive type of gene action observed for majority of the traits. Lines (SLH-284, CIM-473) and pollinators (CIM-707, CIM-496) were leading general combiners for majority of the traits. F 1 hybrids (CIM-473 × CIM-496, SLH-284 × CIM-707 and CIM-446 × CIM-496) which involve best general combiners, showed the leading performance for yield and lint traits. Heritability was moderate to high with appreciable genetic gain for majority of the traits. Except for lint %, the correlation of seed cotton yield was positive with other traits. The significance of additive and non-additive components suggested integrated breeding strategies with delayed selection for development of cotton hybrids with improvement in earliness and seed cotton yield.

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Continued application of organic matter and inorganic synthetic fertilizers to soil influences the nutrient dynamics and diversity of microbial communities. A single site field study (plot size of 9.5 m × 5 m used in each treatment) encompassing 23 years compared the impact of organic and NPK fertilizers for exploring amino acids as indicators of nitrogen fate, and phospholipid fatty acids (PLFA) as biomarkers of microbial diversity in North China Plain field. Treatments in quadruplicated RCBD experiment were: whole N from organic manure (OM); half N from OM + half N from chemical fertilizer (HOM); chemical NPK fertilizers (NPK), NP, NK, PK, and no fertilizer control or check (CK) applied to raise wheat and maize crops continuously. To each crop, N was applied at the rate of 150 kg N ha-1 through organic manure and/or chemical fertilizer urea in two splits (90 + 60 kg N ha-1). Calcium superphosphate (150 kg P2O5 ha-1) and potassium sulfate (150 kg K2O ha-1) were applied basally in respective treatments. Soil samples were drawn from each treatment after 23 years of experimentation. These fertilization amendments exhibited that contents of total nitrogen and amino acids were significantly (p≤0.05) higher under OM and HOM compared to NPK and CK treatments. Total amino acids determination revealed that N and P included treatments among mineral fertilizers mainly contributed to amino acids residues in soil. The PLFA profiling exhibited that increased amino acids under OM and HOM correlated significantly (p≤0.05) and positively with an increase of Gram-positive (G+ve) bacteria and fungi, negatively with actinomycetes, and non-significantly with Gram-negative (G-ve) bacteria. These results suggest that accrual of organic and microbial residues (G+ve bacterial and fungal) enhance the N stabilization in surface soil, which ultimately could increase the plant growth and yield of crops.