外源硫化氢对成龄桃树根系生长的影响

Effects of Exogenous Hydrogen Sulfide on Root Growth of Mature Peach Trees

本试验以7年生‘瑞光33/毛桃’为试材,以NaHS作为硫化氢供体,研究外源硫化氢对成龄桃树根系构型的调控作用,并利用实时荧光定量PCR技术检测外源硫化氢对当年生桃实生苗根系生长素合成及转运编码基因表达的影响,以期为桃树栽培生理研究提供有益参考。结果表明,0.2 mmol·L^(-1)外源NaHS处理能够显著提高成龄桃树根系总长度、根系总表面积、根系总体积、根尖数、分枝数、交叉数和根系分形维数,分别比对照提高12.79%、19.26%、12.86%、12.96%、10.83%、25.28%和2.89%,显著降低根系平均直径17.46%,并显著提高根系活力;尤其显著提高直径0~2.0 mm细根的长度、表面积、体积和干物质积累量,分别比对照提高了15.54%、27.88%、33.52%和36.22%,但对直径>2 mm的粗根没有显著影响。0.2 mmol·L^(-1)NaHS处理桃实生苗2 h后,根系中生长素合成编码基因YUC1和YUC2及生长素转运编码基因AUX1、PIN1、PIN2和PIN3均上调表达。

In this experiment, 7-year-old ‘Ruiguang 33/Maotao’ was used as test material and NaHS was used as hydrogen sulfide donor. The regulatory effects of exogenous hydrogen sulfide(H2S) on root architecture were investigated, and the effects of exogenous H2S on expression of auxin synthesis and transport coding genes in peach roots were detected by real-time fluorescent quantitative PCR, so as to provide useful references for peach cultivation. The results showed that 0.2 mmol·L^(-1)exogenous NaHS treatment significantly increased the total root length, total root surface area, total root volume, number of root tips, branch number, crossings number and root fractal dimension by 12.79%, 19.26%, 12.86%, 12.96%, 10.83%, 25.28% and 2.89%, respectively, significantly reduced the average root diameter by 17.46%, and significantly increased the root activity. In particular, the length, surface area, volume and dry matter accumulation of fine roots with the diameter as 0~2.0 mm significantly increased by 15.54%, 27.88%, 33.52% and 36.22%, respectively compared with the control. But exogenous H2S had no significant effect on thick roots with >2 mm of diameter. After the peach seedlings were treated with 0.2 mmol·L^(-1)NaHS for two hours, the auxin synthesis coding genes YUC1 and YUC2 and auxin transport coding genes AUX1, PIN1, PIN2 and PIN3 were up-regulated in the root system.