Response Of Different Hybrid Rice Genotypes Under Drought Stress During Seedling Stage

Rice(Oryza sativa L.)is one of the important food crops in China as well as entire world.As the request for increasing of production,it need to grow main cereal crops;such as rice,wheat and corn species to maintain the world population.Meanwhile,due to global change,predictions indicate that drought will increase in frequency and intensity over world.Drought is also most restrictive factors for rice growth and development with vegetative and reproductive stages.During vegetative stage,drought can cause reduction in growth and biomass accumulation.Furthermore,water stress at reproductive stage can decrease yield significantly.Rice requires large amount of water throughout its life cycle as compared to other crops.Therefore,water-related stresses cause severe threat to rice production.Drought is a major challenge limiting rice production.It affects rice at morphological(reduce germination,plant height,Biomass weight,various root and leaf traits),physiological(reduce water use efficiency,relative water content,Biochemical(various enzymes such as superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)and molecular(altered expression of genes sequences etc.).Developing a deep root system is an important strategy and plays a critical role for avoiding drought stress mostly in rice plant.This is one of the major mechanisms of drought resistance as thereby affects its yield.This research was carried out to evaluate the adaptation to drought in rice crops during seedling stages.Rice crop is very important economically and food purposes but is known to be drought sensitive.Consequently,it is essential to understand drought response and tolerance of various rice cultivars survive to drought stress.Different characters were determined during seed germination and early-seedling stage.These rice seeds were sown in 2016-2017 at Rice research institute experimental field of Southwest University of Science and Technology China.For this purpose,firstly plant seedling height,Length of leaves and biomass weight were check out among mentioned genotypes under control environment in greenhouse.Further the Relative water content,Roots distribution and the role of various enzymes such as SOD,POD and CAT were recorded among ten cultivars which are selected from first step in trial varieties.In the last suggested genotypes were grown to check out the correlation of DROl gene among rice plant under water stress condition.The above mention parameters were collected when these varieties started to show the signs of drought stress in the form of wilting within various period of time.The results showed that the Rong18 you 447 followed by B501A/xikehui 768 were identified as drought tolerant promising genotypes when grown in harsh environment compared with other trail rice plants.On the other hand,B501A/xikehui 4761 and Chuan 345A/xikehui 1288 are the most vulnerable genotypes when grown in experimental field.The other showed mix response in relation to water stresses.The research highlighted that;Rong18 you 447 is the best species to be cultivated by the farmers and it can provide good vigor and high production for future development.Therefore,it is inferred that water stress was one of the main reasons which decrease rice production.Thus,our finding suggested that the underscored species showed good capacity of water content in plant leaf and soil,biomass weight,possess potent antioxidant defense system,deep roots within different layers.The relation of gene shows good interlink to compared within various parameters mostly in the roots under harsh environment.The identified tolerant cultivars will be a source for rice breeders to develop new drought tolerant genotypes.