不同采集地割手密种质资源的耐寒性评价

Evaluation of Cold Tolerance of Saccharum spontaneum L. Clones Collected from Different Habitats

本研究对不同采集地割手密无性系进行耐寒性综合评价,探究割手密耐寒性与其生长地海拔、纬度的关系,筛选耐寒性种质资源。以40份割手密无性系为试验材料,在苗期低温胁迫后测定各无性系材料的7项生理指标,利用相关性分析、聚类分析和模糊隶属函数分析法对其耐寒性差异进行综合评价。低温胁迫处理后,割手密的脯氨酸(Pro)、丙二醛(MDA)、电导率(PMP)、可溶性蛋含量(SP)均呈上升趋势,其中脯氨酸含量上升最大,升高了43.81%,而叶绿素(Chl)、超氧化物歧化酶(SOD)、过氧化物酶(POD)均呈下降趋势,其中叶绿素含量减少35.01%,下降程度最大;叶绿素、脯氨酸、超氧化物歧化酶的变异系数较对照有不同程度的增加,其中增长最大的是叶绿素,是对照的1.76倍;相关性分析显示,40份割手密无性系耐寒性与其生长地的海拔、纬度呈极显著正相关,相关系数分别为0.867、0.686;模糊隶属函数和聚类分析将40份割手密无性系的耐寒性分为三类,其中高耐寒类型有10份材料,中耐寒性有19份,不耐寒性11份。研究结果表明,不同采集地割手密材料之间耐寒性指标存在明显差异;耐寒隶属函数与海拔、纬度呈极显著正相关,即高海拔和高纬度的割手密耐寒性强、低海拔和低纬度的割手密耐寒性弱,表明在相近海拔范围内决定耐寒性的主要因素是纬度,在相近纬度范围内决定耐寒性的主要因素是海拔。该结果为割手密种质资源在甘蔗耐寒育种中的进一步利用提供依据。

To screen cold tolerance of wild sugarcane germplasms, and to explore the relationship between cold tolerance with original altitude and latitude, the comprehensive evaluation of cold tolerance of clones of Saccharum spontaneum L. from different habitats were performed. After low temperature stress at seedling stage, seven physiological indexes of 40 S. spontaneum clones samples were evaluated using cluster analysis, fuzzy membership function analysis and correlation analysis. Compared with the control group, the contents of Pro, MDA, PMP and SP in the stressed clones increased, in which the content of Pro was the highest by increasing 43.81%. The contents of Chl, SOD and POD decreased, moreover the content of Chl decreased the greatest by 35.01%. The coefficients of variation of Chl, Pro and SOD increased in different degrees, and the biggest increase was found in Chl, which was 1.76 times of the control. The result of correlation analysis showed that the cold tolerance of the 40 S. spontaneum clones was significantly positively correlated with the altitude and latitude of the habitats by correlation coefficients, which was 0.867 and 0.686, respectively. All the 40 S. spontaneum clones were divided into three categories according to the cold tolerance using fuzzy membership function and cluster analysis, in which 10 clones showed high cold tolerance, 19 clones showed medium cold tolerance and 11 clones were cold sensitive. The results showed that there were significant differences in cold tolerance among S. spontaneum clones collected from different habitats, and the membership function of cold tolerance was positively correlated with altitude and latitude, namely the clones collected from high altitude and high latitude had stronger cold tolerance than that collected from low altitude and low latitude habitats. It indicated that latitude is the main factor for the cold tolerance of S. spontaneum clones collected from the same altitude, and altitude is the main factor for the cold tolerance of S. spontaneum clones collected from the same latitude. This work would provide the scientific basis for the further utilization of S. spontaneum clones in sugarcane cold tolerance breeding.