甘蔗高光效新品种筛选与光合潜力分析

Screening of New Sugarcane Varieties with High Light Efficiency and Photosynthetic Potential Analysis

筛选高光效甘蔗新品种并评价其光合潜力可为糖料蔗高质量发展及维护食糖供给安全提供保障。本研究采用叶绿素荧光技术快速测定3个经典的商业主栽品种和10个甘蔗新品种的光反应和暗反应参数,计算基于Lake-model的叶绿素荧光参数,同时用光合电子流(J)对光响应的机理模型拟合光响应曲线,对阴天和晴天下不同甘蔗品种光合电子传递特征参数进行比较分析。结果表明:低光和高光下光能在光合电子传递与可调节性能量耗散(ΦNPQ)之间达到平衡,只有在中光下非调节性能量耗散(ΦNO)在不同品种间出现差异,但这并不代表出现光损伤,而是由于不同甘蔗品种的能量分配在光合有效辐射(PAR)增加的过程中呈现出差异化的过渡模式。所有品种在阴天的初始光能利用率(αe)均高于晴天,但在相同PAR下阴天的光合电子流远低于晴天。热甘16117和热甘1997分别在阴天和晴天的光量子效率(ΦII)最高,热甘16239虽然在中、低光下光量子效率不及ROC22和热甘1997,但其在中光下非调节性能量耗散最低,且在高光下具有较强的饱和光强(PARsat)和最大电子传递速率(Jmax),同时光量子效率与ROC22、热甘1997差异不显著。而基于近5 a试验地阴天和晴天权重占比计算的总和光合电子传递能力指数由大到小依次为:热甘1997(21.93)>ROC22(21.43)>ROC16(20.62)>热甘16239(20.27)>桂柳05136(19.43)>热甘11713(19.30)>热甘1462(19.29)>热甘14291(19.03)>热甘16117(18.94)>热甘1339(18.93)>热甘1876(18.08)>热甘1(17.41)>热甘11559(16.84)。综上,热甘1997和热甘16239可作为甘蔗高光效新品种。

Screening new sugarcane varieties with high light efficiency could guarantee the high-quality development and sugar safety.Chlorophyll fluorescence parameters were measured and calculated from Lake-model for 3 commercial varieties and 10 new varieties to investigate the sugarcane photosynthetic potential under cloudy and sunny day through the mechanism model of photosynthetic electron flux(J)response to light.The results showed that light energy balanced between photosynthetic election transport and regulated energy dissipation(ΦNPQ)under low and high light,the ap-pearance of increased non-regulated energy dissipation(ΦNO)under middle light resulted from the different transition mode among each sugarcane varieties according to increasing photo active radiation(PAR)other than photo-damage.Compared with in sunny day,the initial light utilization rate(αe)of all sugarcane varieties was significantly higher in cloudy day,but J showed sharp decrease at the same PAR level.RG16117 and RG 1997 exhibited the highest photo-quantum efficiency(ΦII)in cloudy and sunny day respectively,which showed no significantly difference between RG16239 and RG1997 under high light.ΦII of RG16239 was lower than ROC22 and RG1997 under low and middle light with the lowestΦNO,but the saturate PAR and maximum J were relatively high under high light.The photosyn�thetic electron transport capacity index(JPT)based on the weight ratio of cloudy and sunny days in recent 5 years ex�posed as RG1997(21.93)>ROC22(21.43)>ROC16(20.62)>RG16239(20.27)>GL05136(19.43)>RG11713(19.30)>RG1462(19.29)>RG14291(19.03)>RG16117(18.94)>RG1339(18.93)>RG1876(18.08)>RG1(17.41)>RG11559(16.84),which made RG1997 and RG16239 high light efficiency varieties.