Are Ashok Kumar

Analysis of genetic variation in sorghum (Sorghum bicolor (L.) Moench) genotypes with various agronomical traits using SPAR methods

Genetic variation among 45 genotypes of sorghum (Sorghum bicolor L.) representing seven subpopulations was assessed using three single primer amplification reaction (SPAR) methods viz., inter-simple sequence repeat (ISSR), random amplified polymorphic DNA (RAPD) and directed amplification of minisatellite-region DNA (DAMD). Totally 15 ISSR, 8 RAPD and 7 DAMD primers generated 263 amplification products, accounting for 84.6% polymorphism across all the genotypes. The Mantels test of correlation revealed the best correlation between ISSR and cumulative data with a correlation coefficient (r) of 0.84. Assessment of population diversity indicated that the maximum intra population genetic diversity was recorded among high FeZn lines (HFL) having maximum values of Neis genetic diversity (h) (0.244), Shannon information index (I) (0.368) and the percentage of polymorphic loci (Pp) (72.65%) while the corresponding lowest values of 0.074, 0.109 and 17.95% respectively were observed among the members of MDT subpopulation. The mean coefficient of gene differentiation (GST) and the gene flow (Nm) between populations were observed to be 0.396 and 0.7680 respectively. The analysis of molecular variance (AMOVA) suggested that maximum genetic variation exists within populations (95%) than among populations (5%). Thus the information obtained from this study could be utilized in sorghum breeding programmes for the development of varieties with improved nutrition and agronomic values in future.

Genetic Variability, Genotype × Environment Interaction, Correlation, and GGE Biplot Analysis for Grain Iron and Zinc Concentration and Other Agronomic Traits in RIL Population of Sorghum (Sorghum bicolor L. Moench)

The low grain iron and zinc densities are well documented problems in food crops, affecting crop nutritional quality especially in cereals. Sorghum is a major source of energy and micronutrients for majority of population in Africa and central India. Understanding genetic variation, genotype × environment interaction and association between these traits is critical for development of improved cultivars with high iron and zinc. A total of 336 sorghum RILs (Recombinant Inbred Lines) were evaluated for grain iron and zinc concentration along with other agronomic traits for 2 years at three locations. The results showed that large variability exists in RIL population for both micronutrients (Iron = 10.8 to 76.4 mg kg−1 and Zinc = 10.2 to 58.7 mg kg−1, across environments) and agronomic traits. Genotype × environment interaction for both micronutrients (iron and zinc) was highly significant. GGE biplots comparison for grain iron and zinc showed greater variation across environments. The results also showed that G × E was substantial for grain iron and zinc, hence wider testing needed for taking care of G × E interaction to breed micronutrient rich sorghum lines. Iron and zinc concentration showed high significant positive correlation (across environment = 0.79; p < 0.01) indicating possibility of simultaneous effective selection for both the traits. The RIL population showed good variability and high heritabilities (>0.60, in individual environments) for Fe and Zn and other traits studied indicating its suitability to map QTL for iron and zinc.

Phenotyping in Sorghum [Sorghum bicolor (L.) Moench]

Sorghum is one of the most important cereal crops grown in the semi-arid tropics (SAT) of Asia, Africa and Americas for its food, feed, fodder and fuel value. Sorghum production is constrained by several biotic and abiotic stresses. Genetic enhancement of sorghum for grain and stover yield, nutritional quality and plant defense traits (abiotic and biotic) which stabilize the crop performance requires thorough knowledge on crop genetic and crop breeding principles. Rapid progress in biotechnology provided powerful and cost-effective molecular/genomic tools to develop desired products in sorghum. However, development of robust and efficient phenotyping methods for traits of interest is critical to make use of these new tools. There is no publication with efficient phenotyping protocols for sorghum research compiled at one place for use by sorghum workers. This book chapter is an attempt to fill that gap and we hope various phenotyping methods discussed hereunder will be useful to sorghum researchers in developing improved products by using them in combination with appropriate breeding/genomic tools.

INVESTIGATION OF BREAST LUMPS: AN EVALUATION

70 patients with 72 palpable breast lumps were assessed by Physical Examination (PE), Mammography (MG), Ultrasound Scan (USS) and Fine Needle Aspiration Cytology (FNAC). The individual and collective value of these investigations have been assessed and a cost effective algorithm suggested.

Botany, Taxonomy and Breeding

Sorghum is one of the most important cereal crops grown in the semi-arid tropics (SAT) of Asia, Africa, and the Americas for its food, feed, fodder, and fuel value. Sorghum production is constrained by several biotic and abiotic stresses. Genetic enhancement of sorghum for grain and stover yield, nutritional quality, and plant defense traits (abiotic and biotic) that stabilize the crop performance requires thorough knowledge of crop botany, diversity, and genetics so as to deploy appropriate crop-breeding strategies. Sorghum is one of the well-understood species in terms of botany, floral biology, and genetic diversity. Both cultivated and wild forms are available in sorghum, which are well distributed in Africa, its center of origin, and in the rest of the world. This chapter describes the botany, floral biology, and classification of sorghum and their implications to the breeding methods to be used. Also this chapter presents how the understanding of botany and taxonomy can be effectively used for improving sorghum yield and nutritional quality traits.