Effect of waterlogging on growth and agronomic trait of different peanut varieties

The growth and agronomic traits of 18 peanut varieties under waterlogging during late vegetative to flowering stage was analyzed. Based on the results, waterlogging decreases plant height, and the number of branches, total pods and full pods. Waterlogging, however promotes pod growth and the ratio of seeds that develop into full pods. Cluster analysis based on agronomic traits is somehow integrated with yield classification after waterlogging (with the 18 varieties classified into 6 types). Some difference exists in waterlogging sensitive varieties, e.g. they do not synchronously change in number and weight of pod and seed. However, the most tolerant varieties (HT type) selectively bred under waterlogging are dwarfed with synchronously increasing number and weight of pod and seed, and promoved ratio of full pod number and ratio of full pod weight. The findings illustrate that waterlogging tolerant eco-breeding is effective. Because more water is demanded in the late vegetative to flowering stage, the impact of waterlogging is limited and even promotes pod and seed development for most waterlogging tolerant varieties so long there is water flow and peanut plants not completely submerged. Therefore, peanut flood impact assessment should focus on flood intensity, growth and development period, and variety tolerance.