Physiological responses of groundnut (Arachis hypogaea L.) to drought stress and its amelioration: A review

Abstract

Groundnut (Arachis hypogaea L.) is an important cash crop for tropical farmers. It is an annual legume and its seeds contain high amounts of edible oil (43-55%) and protein (25-28%). Even though it is fairly drought-tolerant, production fluctuates considerably as a result of rainfall variability. To develop a water stress response function in groundnut, research has been done to improve the performance under varying degrees of stress at various physiological stages of crop growth. This review summarizes recent information on the drought resistance characteristics of groundnut with a view to developing appropriate genetic enhancement strategies for water-limited environments. It is suggested that there are considerable gains to be made in increasing yield and stabilizing the yield in environments characterized by terminal drought stress and further exploiting drought escape strategy, by shortening crop duration. Many traits conferring dehydration avoidance and dehydration tolerance are available, but integrated traits, expressed at a high level of organization, are likely to be more useful in crop improvement programs. Possible genetic improvement strategies are outlined, ranging from empirical selection for yield in drought environments to a physiological-genetic approach. It is also suggested that in view of recent advances in understanding drought resistance mechanisms, the latter strategy is becoming more feasible. It is concluded that the use of this recently derived knowledge in a systematic manner could lead to significant gains in yield and yield stability in the world's groundnut production. Research is needed to develop transferable technologies to help farmers in arid and semi-arid regions. Increasing soil moisture storage by soil profile management and nutrient management for quick recovery from drought are some of the areas which need to be explored.

Nutrient uptakes and their contributions to yield in peanut genotypes with different levels of terminal drought resistance

“…Terminal drought generally reduced pod weight, seed weight, and harvest index (Nautiyal et al, 1999;Reddy et al, 2003) and resulted in yield reduction and low seed quality. Koolachart et al (2013) showed that terminal drought caused 38%-42% yield reduction.…”

“…Since it is mainly grown as a rainfed crop, drought is the most limiting factor, resulting in low yields in many parts of the world (Reddy et al, 2003;Songsri et al, 2008). Frequent failure of rains late in the season has resulted in decreased yield and poor quality peanuts (Kambiranda et al, 2012).…”

Plants responses to drought and shade environments

“…To avoid water loss and evaporation by expanded leaf area, plants decrease individual leaf area, total leaf area per plant and the number of leaves per plant. Eventually, reduction of leaf area by drought decreases plants' growth and photosynthesis (Reddy et al, 2003;Shao et al, 2008).…”

Impact of Drought Stress on Peanut (Arachis hypogaea L.) Productivity and Food Safety

“…Many production areas are in semiarid environments or have unreliable rainfall, and global climate changes and growing demand for fresh water pose major challenges. Physiological adaptation and selection for drought tolerance have been studied by many researchers (Reddy et al, 2003). Study of peanut genomics has been limited by biological constraints, and many basic tools of genomics have yet to be developed (Gepts et al, 2005).…”

“…Peanut is grown on 35.5 million ha across 82 countries in the world. More than half of the production area, which accounts for 70% of the peanut growing area fall under arid and semi-arid regions, where peanuts are frequently subjected to drought stresses for different duration and intensities (Reddy et al, 2003). An annual estimated loss in peanut production equivalent to over US$520 million is caused by dro ught.…”