Rooting Pattern and Anatomical Alteration in Roots of Sugarcane Genotypes under Waterlogged Conditions

Twenty three sugarcane genotypes consisting six commercial varieties (CoLk 94184, BO91, CoS 767, CoJ 64, CoS 97264, UP 9530) and 17 germplasm lines (CoLk 12204, CoLk 12202, CoLk 12206, CoLk 07201, CoLk 04238, LG 06605, LG 04439, LG 05350, LG 05020, LG 03040, A-46-11, B-44-12, A-27-12, D-12-9, D-6-13, S 5085/11, S 5087/11) were assessed for rooting pattern and root anatomy under waterlogged condition. Results indicated in general reduce shoot dry mass in all the genotypes. Except in CoLk94184, CoLk 12204, CoLk 12206, LG06605, LG04439, D-6-13 and S 5085/11, rest of the genotypes showed decreased shoot dry mass. However, root dry mass was observed relatively higher under waterlogged condition. Aerial rooting pattern varied among genotypes as some of the genotypes showed aerial roots up to the 12^th nodes. Genotypes, namely CoLK 94184, UP 9530, CoS 97264, LG 04439, LG 05020, D-6-13, S5985/11 and S 5087/11 genotypes showed dense aerial root growth. Anatomical studies indicated cortical cell distortion and loss of uniformity in endodermis and pericycle due to waterlogging. The size of metaxylem vessel of roots declined when compared with control roots, however, number of metaxylem vessels increased in shoot roots. Correlation analysis indicated positive association of root dry mass (R²=0.655) and number of metaxylem vessel (R²=0.392) with stalk dry weight (yield contributing attribute) under waterlogging condition. Based on root attributes, seven genotypes, namely UP 9530, CoS 97264, LG 04439, LG 05020, D-6-13, S5085/11 and S 5087/11 were defined as tolerant lines exhibiting better tolerance to waterlogging.