Identification of Drought Tolerance Indicators in Interspecific Hybrid Derivatives of Saccharum spp Using Membership Function Value of Drought Tolerance (MFVD)

Drought is the foremost factor that severely affects growth, yield, and its yield components, and has a great impact on sugarcane productivity globally. Identification of drought-tolerant sugarcane cultivars is very important to mitigate climate-related risks to sustain productivity. Hence, it is critical to assess the pre-bred material with wide genetic diversity for drought tolerance for exploitation in breeding. Seventy-five hybrids with improved germplasm base of Saccharum officinarum, Saccharum spontaneum and Saccharum robustum were evaluated at ICAR-SBI, Coimbatore, under drought and normal conditions for yield and physiological traits, for their response under drought. The membership function value of drought tolerance (MFVD) of 19 traits was used as a comprehensive index for evaluation and selection of sugarcane drought-tolerant types. Mean value of all the traits except infrared and canopy temperature depression decreased under drought condition. Cane yield, single cane weight, cane height, soil plant analysis development, total chlorophyll, crop canopy, leaf area, total dry matter, and cane volume depicted > 25% decrease under drought. Leaf width had the highest broad sense heritability (0.69), followed by cane diameter (0.61). MFVD is strongly positively correlated with cane yield and its traits, infrared, leaf length, leaf width, total dry matter, and cane volume. Three genotypes, namely 07-776, 06-021, 20-1132, were highly drought tolerant, and 14-27, 01-807, 07-520, 13-455, 14-54, 04-409, 06-013, 13-644, 07-132 were drought tolerant using MFVD. Regression analysis on nine sensitive traits accounted for 93.1% of the total variation and may serve as indicators for screening sugarcane genotypes for drought tolerance. This new pre-breeding gene pool with high genetic diversity can be utilized in breeding climate resilient types of sugarcane.