Identification of important morphology for waterlogging tolerance from developed mung bean F2 population

Nanthiga Thongthip1, Pasajee Kongsil1, 2, Prakit Somta3, and Tanapon Chaisan1, 2*
Waterlogging is severe abiotic stress during mung bean (Vigna radiata (L.) R. Wilczek var. radiata) production. Waterlogging impacts yield loss for the legume crop by around 40%-70%, depending on the severity and duration of the waterlogging. In total, 107 collected mung bean varieties were evaluated under managed waterlogging. The F2 population from crossing between waterlogging-tolerant and -susceptible mung bean varieties were screened under waterlogging conditions. Morphological responses to the waterlogging were recorded. Correlation and path coefficient analyses were used to identify essential traits for waterlogging tolerance and seed yield potential under water stress. Mung bean varieties in clusters 5 and 6 were high waterlogging tolerance with survival rates of 66.66% and 61.11%, respectively. Of 199 F2 lines from crossings between the Kamphaeng Sean2 and W162, 20 lines presented high waterlogging tolerance. The injury score was negatively correlated with the number of leaves at the final date of waterlogging (-0.845) and 1 wk after terminating the waterlogging (-0.885). At the final date of waterlogging condition, the number of leaves and leaf greenness stability index directly affected leaf injury at -0.5928 and -0.4385. One week after waterlogging termination, only the number of leaves affected the leaf injury at -0.8599. The number of leaves directly affected seed yield components at 0.6534 and higher than the direct effect of the other traits. Thus, the number of leaves was a suitable morphological parameter along with the injury score for selecting waterlogging tolerance. The number of leaves was a suitable parameter for selecting high seed yield potential under waterlogging conditions.
Keywords: Adventitious root formation, cluster analysis, correlation coefficient, injury score, leaf greenness, path coefficient analysis.
1Kasetsart University, Faculty of Agriculture, Chatuchak, Bangkok 10900, Thailand.
2Kasetsart University, National Center for Agricultural Biotechnology, Chatuchak, Bangkok 10900, Thailand.
3Kasetsart University, Faculty of Agriculture at Kamphaeng Saen, Nakhon Pathom, 73140, Thailand.
*Corresponding author (fagrtpc@ku.ac.th).