Study On Yield And Physiological Characteristics Of Rice With Different Canopy Temperature Types

The canopy temperature of rice(average surface temperature of the organs above the ground,referred to as the crown temperature)is different,and the canopy temperature of different varieties is different.Based on this,rice varieties can be classified into different canopy temperature types.In order to investigate the canopy temperature and yield physiological characteristics of rice varieties with different canopy temperature,the paper studied warm rice varieties Fuyu357,Ti09B16,Shen501,SN11-5 and cold rice varieties LDC05-6,Qiaoke 951,SN11-23,SN11-25.By measuring canopy temperature depression,stomatal characteristics,stress resistance,photosynthetic index,yield and panicle traits of rice varieties with different canopy temperature,and conducting comparative analysis,the yield physiological characteristics of rice varieties with different canopy temperatures are determined to provide a breeding practice.Variety selection provides a theoretical basis.The results of the study are as follows:1.In this experiment,during different growth stages of rice,the temperature difference of rice crowns with different crown temperature types showed significant differences.The temperature difference between warm type rice and the crown of rice is significantly lower than that of cold type rice varieties.The temperature difference of the warm type varieties in each growth period is ?2?,and the temperature difference of the cold type varieties is >2?in each growth stage.2.The cold type rice varieties showed a tendency that the stomatal density at the back of the flag leaves is lower than that of the warm type rice at the full heading stage,while there is no significant difference in the stomatal density of the flag leaf ventral surface between the two types of rice varieties.There are no significant differences in the length and width of stomata.3.At the heading stage,the content of soluble protein in flag leaf of cold type rice is significantly higher than that of warm type rice;under normal conditions,there is no significant difference in the relative water content of two types of rice leaf.The correlation analysis also showed that the canopy temperature depression and the soluble protein content are positively correlated with the relative water content.Soluble sugar content of cold type rice leaves is significantly higher than that of warm type rice,but there is no significant difference in malondialdehyde content.This is primarily due to the fact that malondialdehyde is a plant response to stress and is mainly produced under stress conditions.The correlationanalysis showed that the CTD and the canopy is low,and the higher the soluble sugar content is,the higher the correlation coefficient reached the extremely significant level.However,CTD and the malondialdehyde content are negatively correlated,but the correlation is small.The activities of POD,SOD and CAT in leaves of cold type rice varieties are basically higher than those of warm type rice varieties,especially at the booting and heading stages.4.There are different in photosynthetic pigment content among different temperature types of rice.Overall,the relative chlorophyll content of cold type rice varieties is greater than that of warm type rice;the warm type cultivars of Chl a+b and Chl a/b are smaller than those of cold types;Carotenoid content,cold type is also relatively high.From the heading stage to the filling stage,the relative chlorophyll content of the cold type rice decreased less,while the relative chlorophyll content of the warm type rice decreased more significantly.The cold type rice has a longer green leaf period and a slower aging time,which could be utilized.More time for features.At the tillering and heading stages,the net photosynthetic rate,stomatal conductance,and transpiration rate is significantly or extremely significantly positively correlated with CTD,the gas exchange parameters of the cold type rice varieties are relatively large.5.The average number of panicles per hole and yield of cold type rice varieties is greater than of the warm type rice varieties.There is a significant positive correlation between CTD and the 1000-grain weight at the peak of the flood season,full heading stage and filling stage.CTD and the 1000-grain weight has a very significantly positive correlation during the booting stage.