Exogenous application of cytokinin (6-BAP) ameliorates the adverse effect of combined drought and high temperature stress in wheat seedling
Exogenous application of cytokinin (6-BAP) ameliorates the adverse effect of combined drought and high temperature stress in wheat seedling
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外源施用细胞分裂素（6-BAP）改善干旱高温联合胁迫对小麦幼苗的不利影响
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
P. Prakash
中科院分区：
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作者：
Sanam Kumari;Shailesh Kumar;P. Prakash
干旱和高温胁迫经常同时发生，特别是在旱作小麦作物中，在世界上大多数小麦种植区造成严重的产量损失。这两种胁迫对作物生长发育的同时影响可能与单独的胁迫有很大不同，但关于这一主题的研究有限。干旱和高温胁迫抑制了CK的合成，加速了CK的降解，降低了根和地上部的CK水平。用两组不同的小麦品种(C-306，耐性和Ko-307，感病)对10日龄的小麦幼苗进行了单独和复合干旱和高温胁迫条件下的试验。复合胁迫显著降低了膜稳定性、RWC、CSI和光合色素含量，增加了膜脂过氧化产物(TBARS)含量。而外源10ppm BAP(初步试验根据生长和生理特性的变化确定)显著提高了在独立和复合胁迫条件下生长的小麦幼苗的膜稳定指数(MSI)、光合色素含量、叶绿素稳定指数和相对含水量等生长参数。然而，在10日龄的小麦幼苗中，不同的品种受到干旱、高温及复合干旱和高温胁迫的影响。总体而言，干旱+高温胁迫的联合作用比单独胁迫更有害，但交互作用本质上是次加性的，这可能是由于交叉适应效应，进一步外源细胞分裂素(6-BAP)的应用缓解了联合胁迫和单独胁迫的不利影响。
Drought and high temperature stress often occur simultaneously especially in rainfed grown wheat crop causing severe yield loss in most of the wheat growing areas of the world. The simultaneous effects of these two stresses on crop performance in terms of growth and development may be quite different than the individual stress, but there are limited studies on this topic. Drought as well high temperature stress inhibits CK synthesis and accelerates CK degradation, reducing CK levels in roots and shoots. Experiments were performed in 10 days old wheat seedling under independent and combined drought and high temperature stress conditions with two contrasting set of wheat genotypes (C-306, tolerant and Ko-307, susceptible). Combined stress significantly reduced the membrane stability, RWC, CSI and photosynthetic pigments contents and increased the lipid peroxidation (TBARS contents). While exogenous application of optimize dose of 10 ppm BAP, (identified in preliminary experiments based on changes in growth and physiological traits) significant increased membrane stability index (MSI), photosynthetic pigments contents, chlorophyll stability index and RWC and other growth parameters in wheat seedlings grown under independent and combined stress conditions. However, genotypes subjected to drought, high temperature & combined drought and high temperature stress in 10 days old wheat seedlings. Overall it is concluded that, combined effect of drought + high temperature stress was more detrimental than the individual stress however, the interaction effect was hypo-additive in nature, which may be due to cross adaptation effect and further exogenous application of cytokinin (6-BAP) ameliorates the adverse effect of combined stress as well individual stress.