多效唑浸种对NaCl胁迫麻疯树幼苗的生长调节效应

Effects of Seed Soaking in Paclobutrazol on Growth of Jatropha curcas Seedlings under NaCl Stress

以南油1号麻风树幼苗为材料,通过盆栽试验研究了200 mmol·L^-1NaCl胁迫处理对不同浓度（0～1 000 mg·L^-1）多效唑（PP333）浸种麻疯树幼苗生长和光合作用的影响.结果显示：在盐胁迫下,不同浓度的PP333浸种处理均显著降低麻疯树植株株高,但是均显著提高了盐胁迫下株高相对生长速率,同时提高了其干物质积累速率、根含水量、根冠比、叶绿素含量和净光合速率;并提高了幼苗根、叶的K^＋含量,降低根、叶的Na^＋和Cl^-含量,从而提高根、叶的K^＋/Na^＋比率.研究表明,PP333浸种能缓解盐胁迫下麻疯树幼苗的失水程度和光合色素的下降幅度,有效改善其光合作用效率,同时维持体内的离子平衡,从而减轻盐胁迫伤害,促进植株生长,并以600 mg·L^-1PP333浸种效果最好.

In order to evaluate the effects of seed soaking in paclobutrazol（PP333） on salt tolerance of Jatropha curcas seedlings,the relative growth rate（RGR）,dry matter accumulation rate（DMAR）,root water content,root shoot ratio,chlorophyll（Chl） contents,chl a /chl b ratio,net photosynthetic rate（Pn）,K^＋,Na^＋,Cl-contents and K^＋/Na^＋ ratio of J.curcas seedlings treated with 200 mmol·L^-1 NaCl for 10 d with previous seed soaking in different concentrations of PP333 were investigated in greenhouse.The results obtained were as follows：The plant height of seedlings were all decreased significantly with seed soaking in different concentrations of PP333,but the RGR of seedlings increased significantly with all PP333 treatments under salt stress.Under the salt stress,with seed soaking in different concentrations of PP333,the DMAR of seedlings,the root water content,the root shoot ratio,the Chl contents and Pn of seedlings were increased significantly.Under the salt stress,with seed soaking in different concentrations of PP333,the Na^＋ and Cl-contents of roots and leaves of seedlings were decreased;The K^＋ content and the K^＋/Na^＋ ratio of roots and leaves of seedlings were increased.In general,seed soaking in PP333 could enhance the salt tolerance of J.curcas seedlings and the effect of 600 mg·L^-1 PP333 was optimal.Increase of root water content,the Chl contents and Pn,promotion of K＋ uptake in roots and K＋ transport to leaves,decrease of Na＋ and Cl-uptake in roots and transported them to leaves,maintaining the ion homeostasis were the important reasons that seed soaking in PP333 enhancing the salt tolerance of J.curcas seedlings.