Evaluation of early maturing advanced breeding lines of rabi sorghum for drought tolerance

Abstract

Sorghum (Sorghum bicolor (L.) Moench) is a C₄ grass plant, originated from the tropics and generally from more heat and drought tolerant regions. In present study the experiments were conducted in a split plot design with three replications during post-rainy season 2020-21 at Centre on Rabi Sorghum (ICAR-Indian Institute of Millets Research) Solapur under three levels of water regimes (three environments) along with four checks viz., Phule Suchitra, CSV-26, Phule Anuradha & M35-1. Drought tolerant and susceptible genotypes were categorized on the basis of Stress Susceptible Index (SSI), Weighted Geometric Mean index (WGMI) and regression line. Growth Stage -I correlation coefficient between maturity, plant height and panicle length [0.46**] was positive and significant which indicates that as plant height and maturity increases, panicle length also increases. Growth Stage – II correlation coefficient between panicle length and peduncle length [0.62**] was positive and significant, which shows higher the peduncle length, higher will be the panicle length and it is directly related to higher stover yield. Under all environments it was observed that, higher the peduncle length, earlier will be the flowering.  Under GS-1, GS-II and WW environment Correlation between days to 50% flowering, maturity of the plant were [0.44**], [0.56**] and [0.57**] respectively shows positive and significant relationship under all environments. This is the common trait found in all environments. In water stress conditions Phule suchitra (20.07) and DTE-14 (21.14) varieties gave high grain yield as compared to other early verities. In physiological experiment, stomatas were observed in stem leaf and flag leaf which showed that flag leaf played important role in photosynthesis and supply of more energy to the plant for growth and development. The results are first of its kind observed under this study.