Study On The Appraising Indices Of Drought Resistance At The Early Growth Stages And Water Saving Mechanism Of Rice

Water shortage is a world crisis and drought is a difficult problem the whole world must face. According to documents, drought is the roughest natural stress to the production of cereal crops, which equal all other natural element's negative effect on them. China lacks of water resources and the allocation of them is not balanced among the regions and seasons. With the increase of population, urbanization and rapid development of national economy, water supply will be more critical. Paddies' cultivation which consumes 70% of water used by agricultural industry, which consumes 70% of the total consumption of water of the country, is the No.1 water consumer and has great potential of water-saving.Therefore, breeding and screening the variety of paddy which is drought- resistance and cultivating them with economical amount of water is key to sustainable paddy production and food supply and can release the water supply crisis of China. However, in the process of breeding and screening drought resistance varieties and water-saving cultivation, appraisal the drought resistance is the first problem. Although there are massive researches and substantial results at home and abroad, there is still lack of a technique which can appraise the varietals draught resistance quickly and simply in the early growth stage.This research is intended to find such a technique by analyzing and comparing different appraisal times and methods on the basis of previous works. Its main results are as follows:1. In rainless shed different drought resistance of 30 varieties are appraised by the traditional method at booting stageAccording to the preliminary understanding of drought resistance, 30 representative varieties of rice are chose from 500 to be used to carry on booting stage in rainless shed, and then the performance arrangement is defined by taking the drought resistance of yield coefficient as an index. The result provides a reference to the choice of parents in drought resistance breeding, and with its help, 16 varieties which have close growth stage and evidently different extent of drought resistance have been chosen for the farther research.2. The following results are obtained by comparing 16 representative varieties' drought resistance at different growth duration or under different cultivations.1) The arrangements of the extent of drought-resistance differ in different appraisal stages.All the appraisals are carried on in field, and the correlation between drought...