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The critical problem of soybean seed is susceptibility to mechanical processes due to structural limitations of seed and seed coat. The X-radiography of soybean seed revealed the orientation of seed coat around the cotyledons and cultivars like JS 335, JS 9752, JS 71-05, JS 95-60, MACS 124, Pusa 40, Punjab 1 and Type 49 had very compact seed coat around cotyledons. In NRC 12, NRC 37, RKS 18 and SL 525 where the gap between seed coat and cotyledons was significantly very high and non uniform making seed coat very much vulnerable to cracking. Seed coat minerals- calcium, silicon, zinc, iron and lignin content were found to vary significantly among cultivars. Significant genotypic variability for strength of seed coat was observed among the soybean cultivars. A very close relationship was found between strength of seed coat and seed coat compactness. Highly significant correlation was found between mechanical strength and seed coat lignin, iron and zinc content. Quantitative and qualitative variation for seed coat protein among soybean cultivars was revealed and higher protein content was found linked with mechanically strong seed coat. The result revealed that selection for these seed coat parameters in varietal improvement programme may be very fruitful for development of varieties having resistance to field weathering and mechanical damage. [ABSTRACT FROM AUTHOR]

Soybean is a leading oilseed crop in India, which contains about 40% of protein and 20% of oil. Core collection will accelerate the management and utilization of soybean genetic resources in breeding programmes. In the present study, eight agromorphological traits of 3443 soybean germplasm were analysed for the development of core collection using the principal component score (PCS) strategy and the power core method. The PCS strategy yielded core collection (CC1) of 576 accessions, which accounted for 16.72% of the entire collection (EC). The analysis based on the power core programme resulted in CC2 of 402 accessions, which accounted for 11.67% of the EC. Statistical analysis showed similar trends for the mean and range estimated in both core collections and EC. In addition, the variance, standard deviation and coefficient of variance were in general higher in core collections than in the EC. The correlations observed in the EC in general were preserved in core collections. A total of 311 and 137 unique accessions were found in CC1 and CC2 in addition to 265 accessions that were found to be common in both core collections. These 265 common accessions were the most diverse core sets, which accounted for 7.64% of the EC. We proposed to constitute an integrated core collection (ICC) by integrating both common and unique accessions. The ICC comprised 713 accessions, which accounted for about 20.62% of the EC. Statistical analysis indicated that the ICC captured maximum variation than CC1 and CC2. Therefore, the ICC can be extensively evaluated for a large number of economically important traits for the identification of desirable genotypes and for the development of mini core collection in soybean. [ABSTRACT FROM AUTHOR]

Loss of seed quality in soybean is a serious problem in tropical and subtropical region. Foliar application of salicylic acid (SA), GA3 and acetyl salicylic acid (50 ppm) at seedling and pod filling stage, K2HPO4 (2%), α-tocopherol (100 ppm) at flowering and pod filling stage was done on soybean varieties -- NRC 7 and JS 335. Foliar application of SA showed positive effect on seed yield, seed health, germination and seed vigour during storage. Plant height was significantly improved by the GA3 spray in both the varieties. Significantly higher seed yield was obtained with foliar spray of α-tocopherol. Application of SA was found effective to protect plants from various diseases to get quality seed. α-Tocopherol and K2HPO4 treatment significantly reduced MDA production in seeds. α-Tocopherol application increased super oxide dismutase activity as a result the lipid peroxidation of seed during storage was significantly reduced. Application of α-tocopherol, K2HPO4 and salicylic acid improved the storage or keeping quality of soybean seed. [ABSTRACT FROM AUTHOR]

Vitamins of the B group and vitamin C were applied to purple nutsedge (Cyperus rotundus L.) tubers to study their effect on the sprouting rate, initiation and establishment of sprouts, growth of plantlets and development of orthotropic rhizomes in comparison with the corresponding effects of kinetin. Ascorbic acid up to 100 mg l-1 hastened sprouting, whereas vitamins of the B group and kinetin retarded sprouting: 100% tubers sprouted in all treatments within 10 days. Unlike kinetin, none of the vitamins resulted in the establishment of more than one sprout per tuber. Riboflavin and pyridoxine promoted root and shoot growth of the plantlets, whereas kinetin produced short, thick shoots and inhibited root growth, with increasing concentration. Ascorbic acid was only second to kinetin in the induction of orthotropic rhizomes, but the former resulted in an increase in rhizome length.