熱激對甜瓜未授粉子房培養胚珠膨大期內源激素的影響

唐桃霞　孔維萍　任凱麗　程鴻　張化生

摘要：為探究熱激處理對甜瓜未授粉子房培養中胚珠膨大發育與內源激素的影響，以期為揭示胚珠膨大和單倍體培養的機理研究奠定基礎。以熱激和對照培養不同天數的甜瓜未受粉子房為試材，對胚珠膨大率進行動態監測，并采用UPLC-ESI-MS/MS法測定順式玉米素核糖核苷（CZR）、赤霉素3（GA3）、反式玉米素（ZT）、吲哚-3-乙酸（IAA）及脫落酸（ABA）含量，并分析了這5種內源激素與胚珠膨大發育的關系。結果表明，與對照25 ℃室溫培養相比，32 ℃熱激處理4 d有利于胚珠的膨大及內源激素的積累，且在胚珠膨大期5種內源激素的變化趨勢一致，均為遞增。各內源激素間的比例關系處于動態變化中，且在整個膨大期，熱激處理下IAA/（ZT+CZR）、IAA/ABA和IAA/GA3均較對照25 ℃室溫培養高；胚珠膨大率與內源激素IAA呈極顯著正相關，相關系數達0.818，與ZT、CZR和ABA均呈顯著正相關，與（ZT+CZR）/GA3呈顯著負相關。

關鍵詞：甜瓜；未授粉子房；胚珠膨大發育；熱激；內源激素

中圖分類號：S652? ? ? ? ? ? ? 文獻標志碼：A? ? ? ? ? ? ? 文章編號：2097-2172（2023）01-0053-06

doi：10.3969/j.issn.2097-2172.2023.01.013

Effect of Heat Shock on Endogenous Hormones during Ovule Expansion

in Unpollinated Ovary Culture of Melon

TANG Taoxia， KONG Weiping， REN Kaili， CHENG Hong， ZHANG Huasheng

（Institute of Vegetables， Gansu Academy of Agricultural Sciences， Lanzhou Gansu 730070， China）

Abstract： In order to explore the effect of heat shock treatment on ovule expansion and endogenous hormones in unpollinated ovary culture of melon， and to lay a foundation for revealing the mechanism of ovule expansion and haploid culture. The unpollinated ovary of melon cultured for different days under the heat shock and control culture was used as the test material， the ovule expansion rate was monitored dynamically， the contents of cis-zeatin ribonucleoside（CZR）， gibberellin 3（GA3）， trans-zeatin （ZT）， indole-3-acetic acid（IAA） and abscisic acid（ABA） were determined by UPLC-ESI-MS/MS method， and the relationship between these 5 endogenous hormones and ovular expansion was analyzed. The results showed that heat shock treatment was beneficial to ovule enlargement and accumulation of endogenous hormones compared with the control culture at 25℃， and the changes of 5 endogenous hormones in ovule enlargement stage were consistent and increased. The proportional relationship between the hormones was in dynamic change， and the ratios of IAA/（ZT+CZR）， IAA/ABA and IAA/GA3 under heat shock treatment were higher than the control throughout the expansion period. The ovule expansion rate was significantly positively correlated with the endogenous hormone IAA（the correlation coefficient was 0.818）， and was significantly positively correlated with ZT， CZR and ABA， but was negatively correlated with （ZT+CZR）/GA3.

Key words： Melon; Unpollinated ovary; Ovule expansion; Heat shock; Endogenic hormone

單倍體育種技術可以突破傳統選系周期長進度慢的局限［1 - 2 ］，而瓜類作物單倍體育種常采用離體雌核培養途徑。離體雌核發育（in vitro gynogenesis）是指通過未受精子房或胚珠的離體培養，誘導大孢子或雌配子細胞分裂形成胚狀體或經由愈傷組織形成胚狀體，最終產生單倍體（haploid）或雙單倍體（doubled? haploid）植株的過程。為此，前人針對離體雌核發育的影響因素展開了大量研究，如基因型、外植體發育時期、預處理、培養基組成成分和培養條件等，均取得了突破性的進展［3 - 5 ］，但由于離體雌核培養影響因素眾多，發育機制尚不明確，導致誘導技術存在低效性和不可復制性，因而嚴重影響育種應用。……