Differential Root Size Distribution and its Relation to Yield in Contrasting Cultivars of Mungbean under Water Limited environments .

Abstract

A Minirhizotron study of two morphologically contrast mungbean cultivars viz., ML267 and WGG37 under two water treatments of no stress (field capacity) and stress (33.3% of available water content) conditions was conducted at Central Research Institute for Dryland Agriculture, Hyderabad during 2009–10. CRIDA-Pin board method of root architectural sampling was carried out for subjecting them to WinRhizo analysis (WinRHIZO Regular software) for data on total root length, root size, and its temporal distribution vertically besides the root surface area. The results showed that ML267 performed better under moisture stressed conditions (462 kg/ha) as compared to WGG37 (338 kg/ha), which excelled only with sufficient water availability. It is concluded that 36% enhanced pods per plant and 4% increased seed weight resulted in improved ML267 yields by 22% under moisture stressed conditions over WGG37 attributed to maximum total root length and greater fine root length recorded at flowering stage, increased shift of fine roots to deeper soil layers and reduced root surface area at pod filling stage to enhanced sink filling. Hence, ML267 performed better than WGG37 under water-limited conditions. These above mentioned root traits could be indicators of drought tolerance in mungbean plant types.