甘蓝型油菜光合特性及株型性状相关分析

Correlation Analysis of Photosynthetic Characteristics and Plant Type Traits in Brassica napus

选取102份遗传基础广泛的甘蓝型油菜骨干亲本,在油菜初花期使用便携式光合仪6400XT测定光合生理指标,分析102份骨干亲本的光合指标变异情况,运用相关分析探究影响油菜净光合速率的主要因素;同时选取8份代表性材料在苗期和初花期分别测定光合日变化,进一步探究甘蓝型油菜不同发育时期的光合日变化规律。结果表明:102份材料净光合速率变化呈现正态分布,最大净光合速率值为38.15μmol·m^(-2)·s^(-1),最小净光合速率值为11.53μmol·m^(-2)·s^(-1),根据净光合速率大小频率分布将102份材料分为4大类,第Ⅰ类8份(>31.53μmol·m^(-2)·s^(-1)),第Ⅱ类53份(22.53~31.53μmol·m^(-2)·s^(-1)),第Ⅲ类33份(17.53~22.53μmol·m^(-2)·s^(-1)),第Ⅳ类8份(11.53~17.53μmol·m^(-2)·s^(-1));相关分析表明初花期净光合速率与株高(0.123^(*))、主花序长(0.117^(*))、全株角果数(0.130^(*))显著正相关。8份材料苗期和初花期光合日变化表现不完全一致,5份材料苗期呈“单峰变化”趋势、初花期呈“双峰变化”趋势;另外2份材料苗期和花期均呈“单峰变化”趋势;1份材料苗期呈“双峰变化”趋势,初花期呈“单峰”趋势;初花期净光合效率显著高于苗期,均值比苗期高22%;苗期时净光合速率与叶片长度(-0.337^(*))、叶片宽度(-0.508^(**))指标显著负相关,与叶绿素spad值(0.505^(**))极显著正相关,线性回归表明叶片光合强度和单株生物产量线性正相关。研究筛选出在苗期和初花期净光合速率高的材料2份,H2000C和P73-1A;在初花期净光合速率高的材料8份,其中066B和068B-4净光合速率值最高。

In this study,a total of 102 elite B.napus accessions with a broad genetic base were chosen to determine its physiological indicators of leaf photosynthesis by LI-6400XT portable photosynthetic system during early flowering stages,the photosynthesis-index variation of 102 core parents were analyzed to reveal the main factors affecting the net photosynthetic rate of rapeseed.At the same time,the diurnal variation of photosynthesis was explored at developmental stages in B.napus,the photosynthetic diurnal variation of eight accessions was captured at the seedling and the flowering stage.The results showed that 102 accessions’P n presented a normal distribution,the maximum P n was 38.15μmol·m^(-2)·s^(-1),and the minimum one was 11.53μmol·m^(-2)·s^(-1).102 accessions were divided into 4 major categories through the frequency distribution of P n,namely 8(>31.53μmol·m^(-2)·s^(-1)),53(22.53-31.53μmol·m^(-2)·s^(-1)),33(17.53-22.53μmol·m^(-2)·s^(-1)),and 8(11.53-17.53μmol·m^(-2)·s^(-1))accessions,respectively.The results showed that plant height(0.123^(*)),main inflorescence length(0.117^(*)),the number of siliques(0.130^(*))had significantly positive correlation with P n at flowering stage.The diurnal photosynthesis among eight accessions at the seedling and flowering stages were not completely consistent.In detail,five accessions presented a single-peak curve in seedling and a double-peak curve at the flowering stage,one was the completely opposite,and other two lines simultaneously appeared a single-peak curve at both stages.The net photosynthetic rate at the flowering stage showed a relatively higher advantage,with 22%higher on average at the seedling stage.The correlation analysis indicated that P n had significantly positive correlation with chlorophyll(0.505^(**)),however,the negative correlation with leaf length(-0.337^(*))and width(-0.508^(**)).The linear regression indicated that the leaf photosynthetic index and the biological yield per plant were significantly positively correlated.Two accessions(H2000C and P73-1A)with high net photosynthetic rate at the seedling and flowering stages,eight accessions with high-P_(n) at the flowering stage were screened out in this study,in which 066B and 068B-4 had the highest photosynthetic rate.