A new genetic source of drought tolerance in sugarcane

Abstract

Drought is an important limiting factor for crop production and is a serious constraint in many regions of world which affects morphological and physiological traits expression. Ninety seven interspecific hybrids from four different mating groups were planted along with three standards (Co 85019, Co 10026 and CoM 0265). Drought stress was induced during formative phase (60-150 days) of the crop by withholding irrigation. Morphological parameters like cane height, cane weight and Relative water content (%) were studied. Among the mating groups studied, results from improved S. robustum x improved S.officinarum group is presented. Twenty eight vigorous and high tillering types were identified. Wide variations for relative water content (RWC) was observed among the clones under normal and drought. Relative water content was significantly lower in water stressed clones. Among the parents RWC ranged from 52.5% (PIO 88-79) to the highest 83.2% (PIO 14-100) with a mean of 72.58 %. RWC ranged from 38.51 % to 59.66 % in the hybrids of improved S. robustum x improved S.officinarum under drought conditions. Under normal conditions it ranged from 57.62 to 79.11 %. A decrease in cane height (17. 96 %) and stalk diameter (9.64 %) was observed in drought affected canes of mating group involving improved S. robustum and improved S.officinarum. Under drought, nine clones viz., 03-14, 07-435, 20-538, 14-198, 01-807, 07-435, 07-776, 06-028,07-1100 had high RWC and remained green up to maturity stage (360 days). In this group, one clone 14-198 completely dried and two clones 07-50 & 07-520 recovered after drought. Eight clones had high leaf area and recorded high total dry matter in comparison with CoM 0265 and Co 10026. These clones form a new genetic source for use in breeding to develop climate resilient sugarcane clones.