Relationship Between Drought Resistance Of Rice (Oryza Sativa L.) And Some Characteristical And Physiological Indices

The experiments were carried out on the experiment farms of Anhui Agricultural University and University of Science and Technology of China from 2001 to 2002. By using paddy and dry cultivation, and applying Rice cultivation techniches, Plant Physiology, Botany, Cell Biology, Biochemistry, Enzymics and so on, 7 rice cultivars were used to study the relationship between indices of Characters, Physiology, Biochemistry, Yield and Drought Resistance of rice. The major results as follows:1. Some indices of great relationship to drought resistance of riceCorrelation analysis and multiple regression analysis indicated:(1)the yield influence of 5 to 14 characteristic indices, such as the number of general roots, the ratio of the number of white roots to the number of general roots, the volume of roots, the ratio of upland dry weight to general dry weight and the dry weight of root, attained the significant level, F总=331.45**, R2=0. 9910, P<0. 01. (2) the yield influence of 6 to 10 physiological indices, such as the ratio of chlorophyll a to chlorophyllb (chla/chlb), the chlorophyll content, the permeability of plasma membrane in leaves, the free proline content, the root active absorption area and POD, attained the significant level, F总=1342. 90**, R2=0. 9983, P<0. 01. (3) the yield influence of 6 to 24 indices, such as the number of general roots, the ratio of the number of white roots to the number of general roots, the general dry weight, the ratio of upland dry weight to general dry weight, the chlorophyll content and POD, attained the significant level, F总=582. 72**, R2=0. 9949, P<0. 01.2. Relationship of main indices to cultivars of rice and different stageAccording to variance analysis of the number of general roots, the ratio of the number of white roots to the number of general roots, the volume of roots, the ratio of upland dry weight to general dry weight, the dry weight of root, the general dry weight, the ratio of chla to chlb(chla/chlb),the chlorophyll content, the permeability of plasma membrane in leaves, the free proline content, the root active absorption area and POD , the results indicated the relationships of cultivars .different stages andcultivars-different stages all attained the significant level, P<0. 01. But treatments didn' t attain the significant level.3. The general appraisement of drought resistance among different rice cultivars by means of grey relevancy analysis methodFrom above discussion,many indices could be used to apprise the drought resistance, and the rice cultivars with strong drought resistance couldn' t mean they were better in any indice, so it was partial to use one indice to evaluate the drought resistance. The drought resistance of rice could be a general character, which should be analysed through more indices and whose appraisement would be practicable. As a general analysis method, grey relevancy analysis could fusion many indices into relevancy, a kind of indice. According to the relevancy and sequencing on the resistance of different rice cultivars, it would have a rudimentary evaluation on the resistance so that it could afford some grounds for breeding resistance cultivars and cultivating. Among 7 rice cultivars, the drought resistance of YangdaoB was stronger than that of others, and Xieyou63 followed, but the drought resistance of Xiguang was the weakest relatively.