Adaption to Salt Stress and Salt Tolerance Evaluation of Peanut
|School||Hunan Agricultural University|
|Keywords||Peanut(Arachis hypogaea L.) Salt stress Evaluation Stage Growth and development Yield and quality|
Grain produce and the agriculture sustainable development were severely inhibited by the saline soil. Peanut is an important oil and economic crop. Four peanut cultivars were used to study the effects of different salt concentrations on emergence, seedling morphogenesis and matter accumulation. And then the salt tolerance of200cultivars was evaluated by the suitable concentration and index obtained from the former experiment. Further, the effects of salt stress in different stage on the growth and development and produce of peanut was studied used cultivars with different salt tolerant characters. The main results were summarized as follows:1. Effects of different salt concentration on seedling growth of peanutUnder salt stress, the emergence of peanut was inhibited and seedling morphogenesis and matter accumulation was hindered. The dose effect was existed. There were different between cultivars with the same index under different concentrations or with different indices under the same concentration. The salt threshold value of emergence was0.45%. In general, emergence time, plant height, stem height, root volume, leaf number, cotyledon dry weight, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, plant fresh weight and plant dry weight could be as well indices to comprehensive evaluate the salt tolerance of peanut cultivars.2. Salt tolerance evaluation of peanut varietiesThe200cultivars could be divided into four types under salt stress, ie., high salt tolerant type, salt tolerant type, salt sensitive type and high salt sensitive type. Number of cultivars of salt tolerant type was decreased with the increasing salt concentration while salt sensitive type was increased. The number of varieties in no emergence type, tolerant type and sensitive type under0.15%salt concentration was0,136and64, respectively. The number of varieties in no emergence type, tolerant type and sensitive type under0.30%salt concentration was15,80and105, respectively. The number of varieties in no emergence type, tolerant type and sensitive type under0.45%salt concentration was93,22and85, respectively. Salt tolerance of the same cultivar showed similarity or difference under different salt stress. The same cultivar showed tolerance or sensitive under different salt stress. The same cultivar showed tolerance under low salt concentration while sensitive under high salt concentration.3. Salt tolerance evaluation of peanut varietiesFor the salt tolerant variety Huayu25and the salt sensitive variety Huayu20, the growth stage capability of salt tolerance showed the same:pod setting stage> flowerring and pegging stage> seedling stage. The salt sensitive stage was seedling stage.Growth and development of peanut was obviously affected by salt stress. The growth indicies of Huayu25decreased with the increasing salt concentration and all were lower than ck. In the indicies, root fresh weight and shoot fresh and dry weight was decreased74.7%and68.3%. Shoot and root dry weight of Huayu20was increased and then decreased under0.15%salt concentration. All the other indicies were decreased with the increasing salt concentration. Shoot fresh weight was decreased67.4%.Physiological characteristics of peanut was obviously affected by salt stress. With the increasing salt concentration, chla/chlb of peanut leaf was increased while content of chlorophyll a, chlorophyll b and carotenoid was all decreased. Root activity of2cultivars was all decreased by a big margin.Yield and quality of peanut was obviously affected by salt stress at different stage. Under0.15%salt concentration treated at flowerring and pegging stage, there was no pods in2cultivars while the effects was less at pod seeting stage. Number of pegs and weight of pegs and pods was less with the increasing salt concentration. Soluble sugar content in peanut seed was increased while O/Lwas decreased with the increasing salt concentration.