摘 要

以72个喜树家系的功能叶片为研究对象，研究了喜树叶片的叶形及SPAD值，并进行了聚类分析，在此基础上选取10个家系进行了光合特性的研究，并进行了相关性分析，主要结果如下：（1）采用欧式距离和类平均法对72个家系的叶形参数进行聚类，在距离为1.15左右时，将所有家系分成了6大类，其中叶片大小处于两个极端的家系较少。第一类包含4个家系，该类家系的叶形指数最小，在所有类群中最接近圆形。第六类包括3个家系，该类的叶片最小，叶形指数较大。第4类包括4个家系，该类的叶片最大，叶形指数也较大。（2）采用欧式距离和类平均法对72个家系的叶色参数Lab值进行聚类，在距离为4.5左右时，将所有家系分成了5大类，其中叶色参数处于两个极端的家系也较少。第三类包含7个家系，该类的L*、b*值最大，a*值最小；第五类包含2个家系，该类的L*、b*值最小，a*值最大；第二类包含23个家系，该类的Lab值介于第三类和第五类之间。（3）叶形、叶色、光合参数间的相关性较差，而各类参数内部间的相关性较强。叶片大而圆的家系具有较高的Pn和WUE。较圆叶形的家系的叶色越亮，越绿，偏蓝。

关键词：喜树家系，叶形特征，光合特性，SPAD值

Correlation Analysis of Leaf Shape, Photosynthesis Characteristics and SPAD Value of Camptotheca acuminate Families

Abstract: The indexes of leaf shape and SPAD value of 72 Camptotheca acuminata families were studied. Based on leaf shape and SPAD value, the cluster analysis was carried out. 10 families selected according to the clustering result were studied the photosynthetic characteristics. On the above results, the correlation analysis was carried out. The main results are as follows: (1) Based on leaf shape parameters, 72 families were clustered with the Euclidean distance and the class averaging method and divided into 6 categories at the distance of about 1.15cm, of which Large leaf and small leaf families were less. The first group including 4 families have leaf shape index of this family smallest. The sixth group including 3 families has the characteristics of smallest leaves and larger leaf shape index. The fourth group including 4 families has the largest leaves and larger leaf shape index. (2) Based on SPAD values of leaf color parameters, 72 families were clustered with Euclidean distance and class averaging method, and divided into 5 categories at the distance of about 4.5cm, of which the families on leaf color parameters in the two extremes were less. The third group including 7 families have the largest L*, b* value, and the smallest a* value; the fifth group contains 2 families with the lowest L*, b* value and the maximum a* value; the second group contains 23 families, and SPAD value of this group is between the third and fifth groups. (3) The correlation between leaf shape, leaf color and photosynthetic parameters was poor, and the correlations in the Internal of different categories parameters were strong. The large and round families have higher Pn and WUE. Leaf color of the families with a rounded leaf is brighter, greener and bluish.

Keywords： Camptotheca acuminate Families, Leaf Shape, Photosynthetic Characteristics, and SPAD Value.

目 录

引 言 1

1 文献综述 1

1.1 叶形态发育研究进展 1

1.1.1叶的形态结构 1

1.1.2 叶形参数 2

1.2 植物光合性状种质差异及遗传表现研究进展 3

1.2.1植物光合性状的种质差异 3

1.2.2光合性状的遗传 4

1.3叶绿素仪法测定叶绿素含量研究概况 7

1.3.1叶绿素仪法 7

1.3.2 应用叶绿素仪的影响因素 8

2 材料与方法 9

2.1材料 9

2.2方法 9

2.2.1叶形指标测定 9

2.2.2 SPAD值测定 11

2.2.3 光合参数测定 11

3 结果与分析 11

3.1不同喜树家系叶形特征 11

3.2不同喜树家系叶色特征 14

3.3不同家系光合特征 14

3.4叶形、光合和叶色参数间的相关性分析 16

4结论与讨论 18

致 谢 19

参考文献 20

引 言

喜树是长江中下游地区的乡土树种，因地理位置差异形成不同的生态型，叶形态也存在较大差异。叶片形态是构成群体产量能力的重要生物学性状，在水稻育种中，叶片形态改良一直是株型育种的重要目标（陈代波等，2010）。而叶形的改变通常会影响植物体的光合作用、蒸腾作用和抗逆性等生理功能，从而影响植株的生长和发育（张光恒，2007）。因此，研究不同喜树种质资源叶片形态和光合生理变化规律，探索喜树叶形与光合特性、SPAD值之间的相关关系，可为喜树选择育种工作提供理论依据。本研究拟以5个叶形差异较大的喜树家系为材料，测定不同叶位叶片形态指标、净光合速率、气孔导度、胞间CO₂浓度、蒸腾速率和SPAD值，通过方差分析和相关性分析，探讨叶形对光合特性、SPAD值的影响。

1 文献综述

1.1 叶形态发育研究进展

1.1.1叶的形态结构