空间环境对草地早熟禾诱变效应研究Ⅱ——光合特性和叶绿素含量

MUTAGENTIC EFFECTS OF AEROSPACE ON Poa pratensis L.Ⅱ——PHOTOSYNTHESIS CHARACTERS AND CHLOROPHYLL CONTENTS

“神舟3号”飞船搭载草地早熟禾(Poa pratensisL.)‘Nassau’干种子,地面种植后筛选出突变株系PM1、PM2和PM3,分别测定其光合作用光响应曲线、CO2响应曲线及叶绿素含量。结果表明,PM1和PM3株系与对照相比,叶绿素a与b绝对含量降低,且光合能力有所降低。PM2株系比对照叶绿素含量显著增加,且叶绿素a/b比值比对照明显降低,但其表观量子效率较CK低,光合能力也有所降低;3个突变株系的近CO2饱和点均比CK高,CO2补偿点差异不大,羧化效率PM2<CK<PM3<PM1。

The dry seeds of Poa pratensis L. ＇ Nassau＇ were carried by ＂Shenzhou No. 3＂ and three mutants were screened based on presentational characters from the treated plants and asexual reproduced them as PM1, PM2 and PM3. The effects of the space environment on the photosynthesis characters and the contents of chlorophyll of the plants were investigated. Compared to CK, the contents of the chlorophyll a and b were reduced both in PM1 and PM3, and the photosynthetic ability also decreased. The content of the chlorophyll in PM2 increased greatly, but the ratio of the chlorophyll a/b was reduced, and the apparent quantum efficiency and the photosynthetic ability also decreased. The approximately CO2 saturatoion point of the three mutants were higher than CK, but the CO2 compensation points showed no diffenrence between the mutants and CK. The carboxylation efficiency was PM2 〈 CK 〈 PM3 〈 PM1.