马尾松苗木中松醇的分布及其对干旱胁迫的响应

The distribution of pinitol in the masson pine seedlings and its relation with drought stress

对马尾松苗木中松醇的分布及干旱胁迫下不同种源马尾松苗木针叶内松醇含量的变化进行了测定。结果表明:(1)随着苗木的生长,1年生马尾松苗针叶内松醇的含量逐渐增加,到生长季结束时达到最大值。2年生苗木针叶在生长初期松醇含量较高,但随着苗木进入旺盛生长阶段,其含量下降,进入苗木硬化期后,针叶内的松醇含量又有增加的趋势。(2)马尾松苗木茎中松醇含量(DW)最高,达25.86 mg/g,其次是1年生苗的针叶,1年生苗木的根系中松醇含量(DW)最低,仅3.60 mg/g。2年生苗木根系中的松醇含量较高,与针叶中的松醇含量相当。(3)马尾松苗木针叶内的松醇含量随干旱胁迫程度的加深而逐渐增多。胁迫36 d后,5个种源在重度胁迫下的平均松醇含量(DW)为41.38 mg/g,比对照增加25.51%。胁迫54 d后,5个种源在重度胁迫下的平均松醇含量(DW)为47.14 mg/g,比对照增加64.14%。不同种源间马尾松苗木针叶内松醇含量存在较大差异,但胁迫开始时的松醇含量越低,因胁迫松醇的积累越多;在重度干旱胁迫的最后,各种源苗木针叶内的松醇含量比较接近。

The distribution of pinitol in the masson pine seedlings and changes of pinitol content in needles of seedlings from different provenances under drought stress were studied. The results showed that： （1） The pinitol content in one year seedlings gradually increased along with the process of seedling growth and the peak of pinitol content appeared in the end of growing season. The pinitol content in two-year seedlings was high at the beginning of growing season. But it was kept in a low level during the fast-growing period. And the pinitol content increased again in the end of growing season. （2） The pinitol content in the stems was the highest （25.86 mg/g, DW）, followed by needles （22.75 mg/g, DW） and it was the lowest in the roots （only 3.60 mg/g, DW）. （3） The pinitol content in the needles of masson pine seedlings from different provenances increased along with the process of drought stress. The average pinitol content in the needles of seedlings from 5 provenances after 36 days severe drought stress was 41.38 mg/g, DW, 25.51% higher than control. It was 47.14 mg/g, DW after 54 days severe drought stress, 64.14% higher than control. The difference of pinitol content among different provenances was significant at the beginning of drought stress and it was not obvious after three cycles of severe drought stress.