哈密瓜黄绿叶突变体Cmygl-1响应不同光照强度的生理及叶绿素荧光特性

Physiological and Chlorophyll Fluorescence Characteristics of Yellow-green Leaf Mutant in Response to Different Light Intensities

以哈密瓜黄绿叶突变体的幼苗为试材,采用3种不同光照强度处理,研究不同光强对哈密瓜黄绿叶突变体Cmygl-1的生长、叶绿素含量、活性氧的产生、抗氧化酶活性以及叶绿素荧光特性的影响,探索突变体对光照强度的适应特性和选择适合突变体生长的光照强度,以期为耐弱光性品种的选育提供参考依据。结果表明:在无遮光下(A处理)突变体活性氧引起的光抑制损伤严重,轻度遮光则提高了突变体抗氧化酶活性水平,缓解了活性氧伤害;遮光处理下,该突变体的叶绿素含量则较野生型显著增加;与中度遮光(C处理)相比,轻度遮光(B处理)显著提高了突变体的农艺性状,活性氧物质含量降低,抗氧化酶活性升高、光合结构破坏程度减轻。综上所述,突变体在轻度遮光下(B处理)叶绿素含量较高,活性氧积累少,膜脂过氧化程度和质膜损伤小,PSⅡ反应中心活性和电子传递能力高,因此有利于突变体植株的生长。

The seedlings of the yellow-green leaf mutant of cantaloupe were used as test materials.Three different light intensity treatments were used to study the agronomic characters, chlorophyll content, reactive oxygen species and antioxidant enzyme activities, and chlorophyll fluorescence properties of the mutants.The adaptation characteristics of mutants to light intensity and the selection of light intensity suitable for the growth of mutants were explored, in order to provide reference for the breeding of varieties with low light tolerance.The results showed that no shading(treatment A),the active oxygen of the mutant caused severe photoinhibition damage, while light shading increased the antioxidant enzyme activity of the mutant and alleviated the damage of active oxygen;under shading treatment, the chlorophyll content of the mutant was significantly increased compared to the wild type;compared with moderate shading(C treatment),light shading(B treatment) significantly improved the agronomic traits of the mutant, reduced the content of active oxygen substances, increased the activity of antioxidant enzymes, and reduced the destruction of photosynthetic structure.In summary, the mutant had higher chlorophyll content, less active oxygen accumulation, less membrane lipid peroxidation and plasma membrane damage under shading(B treatment),and high PSⅡ reaction center activity and electron transfer ability, which was beneficial to plant growth.