[Effects of water stress and nitrogen fertilization on peanut root morphological development and leaf physiological activities].

Taking 'Huayu 22' peanut as test material, effect of soil water content and nitrogen fertilization on the leaf physiological activities and root morphological characteristics of peanut plants were analyzed. Two levels of soil water condition were: (1) well-watered condition and (2) moderate water stress, and three levels of nitrogen were: (1) none nitrogen (N0), (2) moderate nitrogen (N1, 90 kg · hm(-2)) and (3) high nitrogen (N2, 180 kg · hm(-2)). The results showed that N1 significantly increased the peanut yield under two water conditions, but showed no significant effect on harvest index compared with N0.

[Indices selection and comprehensive evaluation of salinity tolerance for peanut varieties].

A total of two hundred peanut varieties (lines) were exposed to different salt concentrations under pot cultivation, to evaluate salinity tolerance by indices such as emergence, morphology and biomass accumulation from emergence to seedling stage. The results showed that, as the salinity concentration increased, the emergence time was prolonged, plant morphology establishment was inhibited seriously, and biomass accumulation was reduced. The optimal concentration for evaluating salinity tolerance was 0.

[Effects of drought stress on the root growth and development and physiological characteristics of peanut].

Taking two peanut varieties Huayu 17 and Tangke 8 as test objects, a soil column culture experiment was conducted in a rainproof tank to study the peanut root morphological development and physiological characteristics at late growth stages under moderate drought and well-watered conditions. Tanke 8 had more developed root system and higher yield and drought coefficient, while Huayu 17 had poorer root adaptability to drought stress. For the two varieties, their root length density and root biomass were mainly distributed in 0-40 cm soil layer, whereas their root traits differed in the same soil layer.