Research Of The Relationship Between Morphologic And Anatomic Structure And Drought Resistance Of Rice

In order to explore the relationship between the major agronomic traits,leaf morphology,anatomical structure of Asian cultivated rice (Oryza sativa L.) and their drought resistance characteristics, this study on 18 countries from around the world and China's 117 copies of materials from 7 regions in the normal grown under water stress conditions, that made a systematic study of the panicle number per plant, grain number per panicle, spikelet fertility percentage,100-grain weight, biological yield and other agronomic traits, as well as stomatal density, stomatal size, stomatal aggregate, leaf area, wax content, the number of large and small vascular bundle, area ratio of large vascular bundle, number of bulliform cell, area ratio of bulliform cell, depth of bulliform cell et al. total 13 leaf characters, the main results are as follows:1. Agronomic traits and drought tolerance research. Two points of identification results show that the panicle number per plant (Hainan:r= 0.575**; Shanghai:r= 0.427 **), grain number per panicle (Hainan:r= 0.307**; Shanghai:r= 0.316**), spikelet fertility percentage (Hainan:r= 0.299**; Shanghai:r= 0.148*) and drought resistance showed a significant positive correlation. Shanghai Experimental results show that the 100-grain weight (r= 0.186**), straw weight (r= 0.386**), biological yield (r= 0.647 **) and drought resistance reached a very significant positive correlation.2. Morphology and drought tolerance research. Overall, Hainan, Shanghai two years, the experimental results of the two is completely opposite. Stomatal density, stomatal length, stomatal width, pore aspect ratio in the drought treatments were extremely significant differences under normal water and drought stress condition, the experiments show that Hainan:stomatal density increased significantly, significantly reduced stomatal length, stomatal width significantly increased, stomatal length to width ratio significantly decreased, stomatal traits and drought resistance coefficient is not relevant. Shanghai results showed:stomatal density significantly reduced, stomatal length was increased, significantly reduced the width of stomata, stomatal length to width ratio significantly increased, stomatal density and drought resistance coefficient were highly significant positive correlation (r= 0.004**).Leaf area for two years the two experiments showed that the difference between normal water and drought stress have reached a very significant difference (Hainan: P <0.0001**, Shanghai P＜0.0001**), but by drought stress, the Hainan leaf surface active significantly reduced, while the Shanghai leaves positive increased significantly. Hainan results show that the relative leaf area with drought tolerance reach a significant positive correlation (r= 0.023*), while in Shanghai showed no significant correlation (r = 0.402).Stomatal aggregate at two experiments showed that the difference between normal water and drought stress have reached a very significant difference (Hainan:P<0.0001 **, Shanghai P= 0.006**), stomatal aggregate has no significant correlation with drought tolerance (Hainan:P=-0.053, Shanghai P= 0.712). However, under drought stress, the stomatal aggregate decreased in Hainan, but significantly increased in Shanghai.Wax content of the two two-year experiments, has no significant correlation with drought resistance coefficient. Hainan experiments showed that under drought stress has increased, but the trend did not reach significant level (P= 0.073); Shanghai experiment showed that under drought stress, the wax content was significantly reduced and reached a very significant level (P<0.0001**).3. Leaf anatomical structure and drought-related research. The results of the number of large and small vascular bundles, bulliform cells in the two years show that the three characters significantly decreased by drought stress, and reached 0.01 level of significant difference between normal water and drought stress. (Hainan: P the number of large vascular bundles O.0001**, P the number of small vascular bundles 0.0001**, P bulliform cell number 0.0001**; Shanghai:P the number of large vascular bundles= 0.002**, P the number of small vascular bundles<0.0001**, P bulliform cell number 0.0001**). The number of large vascular bundles (Hainan:r= 0.002; Shanghai:r=-0.093), the number of small vascular bundles (Hainan:r=-0.128; Shanghai:r=-0.073), bulliform cell number (Hainan:r=-0.155; Shanghai:r=-0.109) with drought tolerance has no significant correlation.Area ratio of large vascular bundle, area ratio of bulliform cell, depth of bulliform cell had only Hainan experimental results. And the result shows that:area ratio of large vascular bundle (P= 0.2), depth of bulliform cell (P-0.52) has no difference between normal water and drought stress. While the area ratio of bulliform cell reach the 0.05 level difference between normal water and drought stress (P= 0.014*). But rhe three charaters has no significant correlation with drought tolerance.4. Evaluation of drought tolerance. After analysis, the study with a total of 17 indicators is controlled by seven independent factors, factor 1 major dominate the number of bolliform cells, small vascular bundles and large vascular bundles, leaf area, stomatal aggregate, the factor 2 main dominant stomatal length, stomatal density, the factor 3main dominant area ratio of large vascular bundle, wax content, the factor 4 main dominant grains, spikelet fertility percentage, factor 5 main controll stomatal width, ratio of stomatal length and stomatal width, factor 6 main dominant yield, Panicle number per plant, factor 7 main dominant area ratio of and the depth of bulliform cells.