甘薯苗期根系农艺性状与内源激素的动态变化研究

Dynamic Research Between Agronomic Traits and Endogenous Hormone of Roots in Sweetpotato Seedling

为了解甘薯苗期根系生长发育与内源激素之间的关系,通过水培的方法分析了根系农艺性状与内源激素的动态变化,结果表明:在栽后25天内,‘烟薯25’的根长指标一直保持最高,色素提取型甘薯品种Aya和‘济黑1’的平均根鲜重最高,但其平均单株根干重却最低。淀粉型甘薯品种(‘徐薯18’、‘济徐23’)根系在栽后10天就已块根分化完成,并开始了干物质的积累,早于鲜食型甘薯品种(‘济薯22’、‘烟薯25’)和色素提取型甘薯(Aya、‘济黑1’)的根系分化过程。对不同节位根系的内源激素分析发现,尽管6个品种的不同时期、不同节位上根系的内源激素含量变化存在品种间差异,但3个节上根系生长促进类激素(IAA、ZR、GAs)含量在栽后15天左右达到高峰,倒三节根系中的ABA含量低谷也出现在栽后15天左右。对甘薯苗期不同节位根系农艺性状与内源激素间的相关性分析发现,从栽后5天至栽后25天,倒一节根系体积的增大主要与生长类内源激素的平衡紧密相关,生长较为缓慢,而薯苗的倒二节和倒三节根系在栽后20天左右进入了生长的旺盛期,干物质积累迅速。倒一节至倒三节根系分化的时间分别为栽后20天、栽后15天和栽后10天左右,从薯苗基部向上,各节位根系分化时间有逐渐提前的趋势。总之,甘薯苗期不同节位根系的生长、分化特点以及内源激素调控存在时间和空间的差异。

In order to find the relationship between growth and development of sweetpotato root andendogenous hormone, the experiment analyzed dynamic changes for root agricultural traits and endogenoushormone by hydroponics used 1/2 Hoagland nutrient solution. The results showed that root length of‘Yanshu25＇was always higher, and root fresh weight of Aya and‘Jihei1＇was the highest, but its average rootdry weight per plant was the lowest during 25 days after transplanting（DAT）. The storage root of sweetpotato（‘Xushu18＇,‘Jixu23＇） mainly used to process starch had differentiated in 10 DAT and began to accumulate dry matter. The procedure of differentiation of‘Xushu18＇and‘Jixu23＇was earlier than fresh sweetpotato（‘Jishu22＇,‘Yanshu25＇） and purple- fleshed sweetpotato（Aya,‘Jihei1＇）. It was found that endogenoushormone content of root was diversity in different cultivars at different developmental stages and differentnodes. The content of growth promoting hormones such as IAA, ZR and GAs reached peak in 15 DAT, but thecontent of ABA was nearly the lowest in 15 DAT. After correlation between agronomic traits and endogenoushormone was analyzed, root volume of bottom node mainly related to the balance of growth promotinghormones, and grew slowly from 5 DAT to 25 DAT. The root of penultimate node antepenult node grew rapidlyin 20 DAT, and dry matter accumulated speedily. The time of root differentiation form bottom node toantepenult node was respectively in 20 DAT, 15 DAT and 10 DAT. The tendency of differentiated for eachnode up from basic part of sweepotato seedling was gradually ahead of time. In conclusion, spatial and temporaldisparities were found between root growth, differentiation and regulation of endogenous homone in differentnode of sweetpotato seedling root.