秋水仙素处理下蓝蓟花期叶片净光合速率(Pn)日变化的研究

COLCHICINES INDUCED Echium vulgar OF FLOWERING PHASE ON THE DIURNAL VATIATION CHARACTERISTIC OF NET PHOTOSYNTHESIS RATE IN LEAVES

本研究采用不同浓度的秋水仙素和诱导时间不同的蓝蓟种子,大田播种,在蓝蓟不同生长时期使用美国LI-COR公司产LI-6400XT便携式光合仪系统测量蓝蓟叶片的光合日变化,测试结果:叶片净光合速率(Pn)具有"两峰一谷"的不对称双峰曲线,但随着秋水仙素浓度增加和处理时间延迟呈现单峰曲线,浓度0.6%处理24h时净光合速率达到最佳效果,双峰曲线,高峰值为:"24.1μmol·m^(-2)·s^-";秋水仙素浓度0.6%浸泡36h气孔导度(Gs)、胞间二氧化碳浓度(CI)达最高值;秋水仙素浓度0.2%浸泡24h,水分利用率(WUE)最大;不同秋水仙素处理蓝蓟叶片蒸腾速率(Tr)呈"双峰曲线",通过不同处理整体表现为浓度大蒸腾速率较大,但规律性不明显。光合速率日变化与气孔导度呈极显著正相关,与蒸腾速率呈显著正相关。说明秋水仙素浓度大小和处理时间长短对蓝蓟花期光合日变化有直接影响,浓度大、处理时间长光合影响最大,最适合的浓度是0.6%处理,时间是24h。但高浓度、处理时间长抑制了光合作用出现"午休"现象。

This research was used different concentrations of colchicine and inducing time to treat the seeds of Echium vulgare in field. The LI - 6400 XT portable photosynthetic was used to measure the diurnal variation of photosynthetic in the leaves of Echium vulgare during their different growth period. The results showed that the net photosynthetic rate （Pn） of leaves exhibited a asymmetric bimodal curve with ＂two peak - valley＂. However, the Pn appeared a single -peak curve with the increment of the concentration of eolchicine and the delay of treating time. In addition, the Pn achieved the best efficiency when the concentration of colchicine was0.6% and treating time was 24 hours. And, this curve presented a bimodal curve. The maximum value of Pn was 24.1μmol·m^-2·s^-. When the concentration of colchicine was 0.6% and treating time was 36 hours, the stomatal conductance （Gs） and intercel- lular CO2 Concentration （CI） reached their highest values. Moreover, when the concentration of colcbicine was 0.2% and treating time was 24 hours, the Water Use Efficiency （WUE） exhibited the highest value. The transpiration rate （Tr） of Echium vulgare leav- es with different concentrations of colchicine showed a bimodal curve. The concentrations were high for the overall treatments, as well as their corresponding Tr. But this regularity was not obviously. Furthermore, a positive correlation was between the Pn and Gs （p 〈 0.01 ）, Tr （p 〈 0.05）, indicating that the colchicine concentration and treatment time directly affected the photosynthetic diurnal var- iation of Echium vulgare florescence. When the colchicine concentration was higher and the treatment time was longer, the influence of photosynthesis was higher. The concentration of colchicine was 0.2% and treating time was 24 hours, which were the best combi- nation for this study. The photosynthesis was suppressed with ＂lunch break＂ phenomenon due to the higher concentration of colchicine and longer treating time.