不同种源辽东栎种子和幼树指标变异及相关分析

Variation of seed and sapling indexes of Quercus liaotungensis from different provenances and related analyses

在山西、甘肃、河北、陕西和辽宁采集12个辽东栎(Quercus liaotungensis Koidz.)种源的种子,对不同种源的种子指标(包括发芽率、种子长度、种子宽度、单粒种子质量、单粒种子体积和碗疤直径)和幼树指标〔包括壮苗指数、根长比、单叶面积、单株分枝数、节间长度以及叶片的快速叶绿素荧光诱导动力学参数和叶绿素相对含量(SPAD)〕进行变异分析,在此基础上,对这些指标间及其与种源地的地理位置和环境因子(包括气候因子和土壤因子)进行Pearson相关性分析,并基于不同类型指标对供试种源进行Heatmap聚类分析。结果表明:发芽率、种子长度、种子宽度、单粒种子质量、单粒种子体积、碗疤直径、壮苗指数、根长比、单叶面积、PSⅡ单位面积有活性反应中心数(RC/CSo)、PSⅡ单位反应中心(RC)用于将电子从Q-A传递到质体醌(PQ)的能量(ETo/RC)、PSⅡ单位反应中心用于将电子从Q-A传递到PSⅠ受体侧的能量(REo/RC)和性能指数(PIABS)的种源间差异显著(P<0.05)或极显著(P<0.01)。种子和幼树指标的种源间变异系数均值(分别为27.81%和20.58%)小于个体间变异系数均值(分别为32.36%和30.01%),其中,发芽率、种子宽度和壮苗指数的种源间和个体间变异系数较大。各种子指标及幼树的壮苗指数、单叶面积和RC/CSo的种源重复力大于0.9。相关性分析结果表明:部分指标间及其与种源地的地理位置和环境因子的相关性显著或极显著,例如,发芽率与种源地的昼夜温差月均值以及5月份、6月份和10月份的太阳辐射强度呈显著正相关,相关系数分别为0.59、0.65、0.60和0.61;壮苗指数与种源地的年均温变化范围、最湿月降水量和上层土壤沙含量分别呈显著、极显著和显著正相关,相关系数分别为0.67、0.74和0.67。聚类分析结果表明:不论以种子指标、幼树指标、种源地环境因子还是所有指标进行种源聚类,河北围场和辽宁海城种源与其他种源均明显分开。结果显示:辽东栎种子和幼树指标变异丰富,且以个体间变异为主;育种时可根据发芽率、种子宽度和壮苗指数进行单株筛选。

Seeds of Quercus liaotungensis Koidz.were collected from 12 provenances in Shanxi,Gansu,Hebei,Shaanxi,and Liaoning,and variation analysis was conducted for seed indexes(containing germination rate,seed length,seed width,single seed mass,single seed volume,and cupule scare diameter)and sapling indexes〔containing seedling index,root length ratio,single leaf area,branch number per plant,internode length,and kinetic parameters of rapid chlorophyll fluorescence induction and relative chlorophyll content(SPAD)in leaf〕of different provenances were analyzed,on the basis,Pearson correlation analyses were performed among these indexes and between them and geographical locations and environmental factors(containing climatic factors and soil factors)of origins,and Heatmap cluster analysis was conducted for the test provenances based on different types of indexes.The results show that the differences in germination rate,seed length,seed width,single seed mass,single seed volume,cupule scare diameter,seedling index,root length ratio,single leaf area,density of reaction centers of PSⅡ(RC/CSo),the flux of electrons transferred from Q-A to plastoquinone(PQ)per reaction center(RC)of PSⅡ(ETo/RC),the flux of electrons transferred from Q-A to PSⅠacceptors per RC of PSⅡ(REo/RC),and performance index on absorption basis(PIABS)among provenances are significant(P<0.05)or extremely significant(P<0.01).The means of coefficient of variation of seed and sapling indexes among provenances(which are 27.81%and 20.58%,respectively)are smaller than those among individuals(which are 32.36%and 30.01%,respectively),in which,the coefficients of variation of germination rate,seed width,and seedling index among provenances and individuals are relatively large.The provenance repeatability of each seed index and seedling index,single leaf area,and RC/CSo of sapling are greater than 0.9.The correlation analysis results show that the correlations among part indexes and between them and geographical locations and environmental factors of origins are significant or extremely significant,for example,germination rate shows significant positive correlations with monthly mean diurnal range of temperature and solar radiation intensity in May,Jun.,and Oct.of origins,the correlation coefficients are 0.59,0.65,0.60,and 0.61,respectively;seedling index shows significant,extremely significant,and significant positive correlations with annual mean temperature range,precipitation of the wettest month,and sand content in upper soil of origins,respectively,the correlation coefficients are 0.67,0.74,and 0.67,respectively.The cluster analysis result shows that whether the provenance cluster based on seed indexes,sapling indexes,environmental factors of origins,or all indexes,provenances from Weichang of Hebei and Haicheng of Liaoning are clearly separated from other provenances.It is suggested that the variations of seed and sapling indexes of Q.liaotungensis are abundant,and the variations among individuals are main.Individual selection in breeding can be performed based on germination rate,seed width,and seedling index.