The Study Of The Canopy Temperature And Physiological Characteristics Of Cotton

The crop canopy temperature and its related physiological characteristics of cotton are not only varied with the genotypes but also influenced with the climate and soil, and related with the high burliness and the productivity. In order to clarify the differences of the crop canopy temperature and its related physiological characteristics of the different genotypes, this paper focus on the study of the characters of the functional leaf senescence and the activated oxygen metabolism through the comparative study of the Liaomian 1 hao (served as reference), Zhongmian 41 hao, Paotai 1 hao,Yu422, Zhongmian 5629. We measured the co㎜ unity canopy temperature, the content of the chlorophyll and the Soluble protein, the activity of the SOD and MDA at the florescence under the same conditions. The results showed that the content of the chlorophyll and the Soluble protein of the cold type cotton decreased more slowly than that of the warm type cotton, with quite high activity of the SOD and NR but decrease to a quite small extent. The accumulation speed of the MDA of the cold type cotton is also more slowly than that of the warm type cotton. These results indicated that the canopy temperature can be a external signature of the metabolic function of the cotton, and can provide the theory basis for the cotton breeding in the field practice.1. Different genotypes of cotton canopy temperature differentiation phenomenon exists since the flowering period to the opening of a boll, different genotypes of cotton varieties Canopy temperature of a differentiation, some low, some 1982-98. CCRI 41 on the 1st and Fort temperature mostly in the baseline, the temperature is low. and Henan 422 and the 5629 Cotton temperature mostly in the base line, a higher temperature. Canopy temperature of the sequence changes in the significant results indicate that temperature-the difference between cotton have reached a significant level; the canopy temperature variation of the significant analysis, in the time-temperature difference between the differential has almost reached a significant or very significant level.2. Different genotypes of cotton physiological characteristics there is a difference of(1) Hypothermia cotton chlorophyll content in full bloom after consistently holders at a high level, its chlorophyll content with the growth period of degradation goes faster than cotton gently warm, This shows that the low-temperature cotton higher energy use efficiency, with the potential anti premature senility. Significant results show that the different temperatures between the type of cotton, CCRI 41, and Yu 422 and cotton between 5629 there were significant, But on the 1st and Fort yu 422 and cotton between 5629 has not reached a significant level.(2) Hypothermia cotton in various periods of soluble protein content higher than that of almost all warm cotton, in the late childbearing, soluble protein content decreased faster, but the low-temperature decrease in cotton slightly lower than warm cotton, again confirmed its metabolic function better than warm cotton. Significant results show that the different temperatures between the cotton-exist significant differences, Fort on the 1st and cotton difference between the 5629 is now at a very significant level.(3)Hypothermia cotton-cotton than at most times in maintaining high SOD activity, decline rates are relatively slow, Note hypothermia cotton has strong reduce reactive oxygen peroxide or other free radical damage to the membrane system, metabolic function better. Significant results show that the different temperatures between the type of cotton, CCRI 41, and Yu 422 and cotton between 5629 there were significant differences Fort on the 1st and cotton between 5629 there were significant differences But on the 1st Battery 422 between Henan and has not reached a significant level.(4)Hypothermia cotton nitrate reductase activity in each period remained relatively high activity, in the latter part of the decline in fertility rates are relatively slow, Note the low-temperature cotton than warm cotton with high nitrogen use capacity, high-yield basis. Significant results show that the different temperatures between the type of cotton, CCRI 41, and Yu 422 and cotton between 5629 there were significant differences But on the 1st and Fort yu 422 and cotton between 5629 did not reach significant levels.(5) Different genotypes of cotton leaves MDA with the passage of reproductive age have been showing a rising trend, Cotton low temperature increase is slow, less accumulation, warm cotton increased faster accumulation, Cotton showed low temperature membrane lipid peroxidation lesser extent, again confirmed its metabolic function better than warm cotton. Significant results show that the different temperatures between the type of cotton, CCRI 41, and Yu 422 and cotton between 5629 there were significant differences Fort on the 1st and Henan between 422 also reached a significant level, But Fort on the 1st and cotton between 5629 failed to reach a significant level.(6) In the opening of a boll, the temperature was mild hypothermia cotton cotton difference soluble sugar content increases, Cotton hypothermia maintain a higher soluble sugar content, Cotton proved that the low temperature than warm cotton in the late stronger with the osmotic adjustment capacity, better ability to resist adversity. Significant results show that the different temperatures between the type of cotton, CCRI 41 with cotton between 5629 there were significant differences, the other did not reach the significant level.3. Different genotypes of cotton stomatal characteristics of the existence of exchange differences(1) Hypothermia cotton in various periods of the transpiration rate is high in warm cotton. High transpiration rate is not only beneficial to the plant to lower the temperature, but also for the growth and development of plants provide more mineral nutrients, and for the smooth conduct photosynthesis provide a more adequate moisture, It will facilitate access to reverse CO2 significantly in vivo analysis of the results showed that the different temperatures between the type of cotton, CCRI 41, and Yu 422 and cotton between 5629 there were significant differences Fort on the 1st and cotton between 5629 up to a significant level, But on the 1st Battery 422 between Henan and not statistically significant level.(2) With the advance of reproductive age, low cotton WARM_TEMPERATE cotton leaf net photosynthetic rate and the difference increased, hypothermia cotton leaf net photosynthetic rate significantly higher than that of warm cotton, which increase the yield created very favorable conditions. Significant results show that the different temperatures between the type of cotton, CCRI 41, and Yu 422 and cotton between 5629 there were significant differences Fort on the 1st and cotton between 5629 up to a significant level, But on the 1st Battery 422 between Henan and not statistically significant level.(3) Hypothermia cotton than warm cotton in different periods of time have a higher stomatal conductance, stomatal conduction ability, Metabolic Function exuberant. Significant results show that the different temperatures between the cotton-exist significant differences.4. Different genotypes of cotton yield differences hypothermia cotton than warm cotton buds with a lower rate and higher exfoliated The yield, two temperature-cotton lint yield and Leiling expulsion rate reached a significant difference.