坛紫菜耐低盐品系的选育与特性分析

SELECTION AND CHARACTERIZATION OF A LOW-SALINITY TOLERANT STRAIN IN PYROPIA HAITANENSIS(BANGIALES,RHODOPHYTA)

本实验室采用人工诱变技术获得一个坛紫菜耐低盐品系(YZ-7),为了验证该品系的耐低盐性状能否遗传,本文对其壳孢子和F1叶状体的低盐耐受性分别进行了测试,并以坛紫菜野生品系(WT)作为对照,结果表明:在不同盐度下培养2周的YZ-7和WT的壳孢子,在26盐度组存活率无显著差异;在15盐度组,YZ-7的壳孢子存活率和假根发生率分别比WT提高了34%和35%;在8和5盐度组,YZ-7的壳孢子存活率、分裂率及假根发生率分别比WT提高了65%、32%和62%,以及137%、80%和154%;在3盐度组,YZ-7的壳孢子存活率和分裂率分别比WT提高了458%和171%,其中约44.9%的YZ-7壳孢子萌发体能形成假根,而WT的壳孢子萌发体基本上不长假根。在26盐度中培养35d后的F1叶状体再分别在26、15、8、5和3盐度下培养30d,YZ-7叶状体的特定生长率分别为WT的1.7、1.9、1.5、1.6和1.6倍,绝对生长率分别是WT的3.4、4.1、1.8、2.0和1.6倍。此外,YZ-7叶状体的叶绿素荧光活性(PSⅡ最大光量子产量、实际光量子产量)及三种主要光合色素(叶绿素a、藻红蛋白和藻蓝蛋白)的含量也明显高于WT。上述结果证实,坛紫菜选育品系YZ-7是一个耐低盐且生长快的优良品系,其优良性状可稳定传递给下一代,有望被培育成适宜栽培的新品种。

Alow-salinity tolerant strain(YZ-7) was selected by artificial mutagenesis in our laboratory.The tolerance of YZ-7 conchospores and F1 gametophytic blades to low-salinities was studied against the wild-type(WT) as the control in salinities of 26,15,8,5,and 3 for 2 weeks.The results show no significant difference in survival rate between YZ-7 and WT at normal salinity 26.In the 15 salinity group,the survival rates and the rhizoid germination rates of YZ-7conchospore germlings were 34% and 35% higher than those of control,respectively.In 8 and 5 salinity groups,the survival rates and division rates of conchospores,and the rhizoid germination rates were 65% and137%,32% and 80%,62% and 154% higher than those of the control,respectively.In the group of lowest salinity at 3,the survival rates and division rates of YZ-7 conchospores were 458% and 171% higher than those of control,respectively,and 44.9% of YZ-7 but zero WT conchospore germlings had rhizoid germinated.In addition,we took YZ-7 blades that cultured in normal salinity 26 for 35 d and then transferred them into different salinities for another 30 days in the same salinity spectra mentioned above.The results show that the absolute growth rates of YZ-7 blades were 6.85,8.24,4.15,5.80,and 2.88 times higher; specific growth rates were 2.57,2.63,2.79,4.05,and 3.90 higher than those of WT,respectively to the salinities.In chlorophyll fluorescence activities(Fv/Fm and Yield) and contents of three main photosynthetic pigments(chl a,PE,and PC),those of YZ-7 blades were significantly higher than those of WT.Therefore,YZ-7 were proved as a low-salinity- tolerant fast-growing strain whose traits could be passed onto the next generation,and be a potential new cultivar.