旱涝急速转换对超级杂交晚稻秧苗素质及叶片内源激素水平的影响

以超级杂交晚稻五丰优T025为材料,于苗期进行了"不旱不涝"(NDNF)、"重旱不涝"(SDNF)、"不旱轻涝"(NDLF)、"重旱重涝急转"(SDSFAA)、"重旱轻涝急转"(SDLFAA)、"轻旱重涝急转"(LDSFAA)等处理,考查了株高,叶龄,茎宽,白根数,干物质量等秧苗素质指标及叶片内源激素含量。结果表明:"涝"或"旱涝急转"胁迫处理后,短期内不同程度降低秧苗素质;随着胁迫的解除及生育推进,各处理秧苗素质指标与对照"不旱不涝"间的差距均不同程度缩小;其中进行一定程度的干旱处理,恢复供水后有利于秧苗白根数的形成及干物质积累,提高秧苗素质,旱后复水存在生长补偿效应;旱后任何程度的淹涝处理均不利于壮苗的形成,其中旱后重涝急转处理下秧苗徒长,白根数大幅度下降及干物质积累减少,旱后重涝急转叠加损伤效应明显;"涝"或"旱涝急转"胁迫处理后短期内均不同程度提高倒二叶ABA及IAA含量,降低GA_3及ZR含量;随着胁迫的解除及生育的推进,"重旱重涝急转"GA_3、ZR及IAA含量在所有处理中下降幅度最大,而ABA含量下降幅度最小,旱涝急转不利于生长促进类激素形成,但造成生长抑制类激素的积累;所有不同类型旱涝急转处理结束初期均大幅度降低倒二叶(IAA+GA_3+ZR)/ABA值,但随着生育推进将反超"不旱轻涝"。

Effects of Abrupt Drought-flood Alternation on Seedling Quality and Content of Endogenous Hormone of Leaves in Super Hybrid Late Rice

Super hybrid late rice Wufengyou T025 was selected as the material and the rice plants were treated with no drought followed by no flood ( NDNF),serious drought followed by no flood ( SDNF),no drought followed by light flood (NDLF),serious drought followed by serious flood abrupt alternation ( SDS?FAA),serious drought followed by light flood abrupt alternation (SDLFAA),and light drought followed by se?rious flood abrupt alternation ( LDSFAA) during the seedling stage,while seedling quality indexes of plant height,leaf age,stem width,white roots,dry matter weight and endogenous hormone in leaves were inspected. The results were as follows:‘Flood’ and ‘drought followed by flood abrupt alternation’ decreased seedling quality to a certain extent in a short time after treatments,however,the gaps of the seedling quality indexes be?tween the treatments and the control NDNF narrowed to a certain extent along with the stress relieved and growth advance.A certain extent drought treatment then water application recovery was in favor of the formation of white root and dry matter accumulation to increase seedling quality,which indicated that there was growth compensatory effects for water recovery after drought.It was disadvantageous to healthy and strong rice seedling formation for any degree flood treatment after drought,and drought followed by serious flood abrupt alternation resulted in excessive seedlings growth of,white roots and dry matter accumulation declined substantially,sug?gesting that there was superimposing harm to rice plant from drought followed by serious flood abrupt alterna?tion.Flood and drought followed by flood abrupt alternation increased indole?3?acetic acid (IAA) and abscisic acid (ABA) contents in the reciprocal second leaf to a certain extent,while decreased gibberellin A3 (GA3 ) and zeatin riboside (ZR).Along with the stress dissolution and growth advance,the decline rates of GA3 ,ZR and IAA for SDSFAA were the most and ABA the least among all the treatments.Drought followed by flood ab?rupt alternation was disadvantageous to the formation of growth promoting hormones and brought the accumula?tion of about growth inhibiting hormones.All the different types of drought-flood abrupt alternations decreased (IAA+GA3+ZR) / ABA substantially at the initial stage after treatments,however,along with growth advance it overtook NDLF.