生长物质对彩色棉胚珠离体培养纤维发育的影响

Effects of Growth Substances on the Fiber Growth and Development of Color Cotton Ovule Culture in vitro

【目的】天然彩色棉是理想的绿色、环保、健康纺织原料,建立并优化棕色棉和绿色棉胚珠离体培养体系,研究渗透压调节剂、植物生长调节剂和类黄酮代谢前体物质等生长物质对彩色棉胚珠培养纤维发育的影响,为彩色棉纤维色泽改良提供一定的理论基础。【方法】以棕1-61、RT白絮、绿棉CC28为材料,采用常规栽培管理方法种植,在开花当天标记棉铃,取开花后3 d的棉铃进行离体培养。所有处理均在BT培养基基础上添加10.0μmol·L-1的IAA和5.0μmol·L-1的GA3,此外分别采用不同浓度的渗透压调节剂(甘露醇、氯化钠、氯化钾、蔗糖)、植物生长调节剂(茉莉酸甲酯、油菜素内酯)和类黄酮代谢前体物质(苯丙氨酸、阿魏酸)进行处理。除了考察油菜素内酯和茉莉酸甲酯交互作用的试验外,其他均为品种和处理的双因素试验。在离体培养30 d后观察纤维显色状况、测量纤维长度并称取胚珠鲜重、纤维干重和胚珠干重。试验中每个处理的数据均计算平均数和标准误,主要采用最小显著差数法或新复极差法进行多重比较。【结果】离体培养条件下彩色棉纤维在培养后15 d显色;适合彩色棉胚珠生长和纤维发育的最佳处理为5 g·L-1蔗糖,其中棕1-61纤维长度、胚珠鲜重、纤维干重和胚珠干重比对照分别显著增加28.35%、20.69%、103.70%和75.84%(P<0.05),绿棉CC28纤维长度、胚珠鲜重、纤维干重和胚珠干重比对照分别显著增加8.10%、16.07%、63.14%和82.76%(P<0.05);0.05μmol·L-1Me JA处理时棕1-61纤维长度比对照显著增加22.90%(P<0.05),CC28纤维长度对照增加4.39%,差异不显著;0.5μmol·L-1BR处理使棕1-61、CC28纤维长度分别比对照显著增加22.46%和11.56%(P<0.05);25μmol·L-1阿魏酸处理下棕1-61、CC28纤维长度分别比对照显著增加了8.72%和8.81%(P<0.05);添加适宜浓度的甘露醇(30 g·L-1)、氯化钠(0.10mol·L-1)、氯化钾(0.20 mol·L-1)、蔗糖(10 g·L-1)、茉莉酸甲酯(40μmol·L-1)或者苯丙氨酸(0.10 mmol·L-1)有利于棕色棉显色,其中40μmol·L-1茉莉酸甲酯效果最好;试验所用的生长物质处理下,绿色棉显色差异不大。【结论】蔗糖为彩色棉胚珠生长和纤维发育提供了糖源和渗透环境;适宜浓度的茉莉酸甲酯、油菜素内酯或阿魏酸有利于棕色棉和绿色棉纤维伸长发育;油菜素内酯和茉莉酸甲酯存在交叉作用,油菜素内酯主要参与纤维伸长过程中,而茉莉酸甲酯可能参与到棕色棉色素代谢过程中;一定浓度的甘露醇、氯化钠、氯化钾、蔗糖、茉莉酸甲酯或苯丙氨酸有利于棕色棉色素合成;渗透压调节剂、植物生长调节剂和类黄酮前体物质对绿色棉纤维显色作用不明显。

【Objective】 In order to establish and optimize the ovule culture system of brown cotton and green cotton,the effects of growth substances（osmotic regulators,plant growth regulators and flavonoids biosynthesis precursors） on the fiber growth and development were studied.【Method】Brown cotton variety Z1-61,green cotton variety CC28 and the white cotton variety RT-White（control sample） were used as plant materials.The conventional ways of cultivation and management were adopted.Flowers were tagged at 0 day post anthesis（DPA）,and then the ovules of 3 DPA were used for ovule culture in vitro.Besides the addition of 10.0 μmol·L^-1 IAA and 5.0 μmol·L^-1 GA3,different concentrations of osmotic regulators（mannitol,Na Cl,KCl and sucrose）,plant growth regulators（Me JA and BR） and flavonoids biosynthesis precursors（phenylalanine and ferelic acid） were added to the basic BT medium,respectively.Except investigating the interaction effect between brassinolide and methyl jasmonate,the other experiments were chosen variety and treatment for dual factors test.After being cultured in vitro for 30 days,the fiber color,fiber length,ovule fresh weight,ovule dry weight and fiber dry weight of Z1-61,RT-White,and CC28 were determined.The mean value and standard error were calculated and multiple comparisons were carried out using least significant difference（LSD） or shortest significant ranges（SSR）.【Result】Color cotton pigmentation was observed until 15 d after ovule culture in vitro.The best treatment for color cotton ovule growth and fiber development was 5 g·L^-1 sucrose,under which the fiber length,ovule fresh weight,fiber dry weight and ovule dry weight of Z1-61 was significantly increased by 28.35%,20.69%,103.70% and 75.84%（P〈0.05）,while that of CC28 was significantly increased by 8.10%,16.07%,63.14% and 82.76%（P〈0.05）,respectively,compared with the controls.In 0.05 μmol·L^-1Me JA treatment,the fiber length of Z1-61 was significantly increased by 22.90%（P〈0.05）,while that of CC28 was increased by 4.39%.In 0.5 μmol·L^-1 BR treatment,the fiber length of Z1-61 and CC28 was significantly increased by 22.46% and 11.56%（P〈0.05）,respectively.In 25 μmol·L^-1 ferelic acid treatment,the fiber length of Z1-61 and CC28 was significantly increased by 8.72% and 8.81%（P〈0.05）,respectively.Furthermore,30 g·L^-1 mannitol,0.1 mol·L^-1 Na Cl,0.20 mol·L^-1KCl,10 g·L^-1 sucrose,40 μmol·L^-1 methyl jasmonate or 0.10 mmol·L^-1 phenylalanine were conducive to the pigment accumulation of brown cotton fiber.Among them the best treatment was 40 μmol·L^-1 Me JA.However,the growth substances used in this experiment did not cause any significant change in the pigment appearance of green cotton.【Conclusion】Sucrose provided the sugar source and osmotic environment for color cotton ovule growth and fiber development,and the appropriate concentrations of Me JA,BR or ferulic acid benefited the fiber elongation.There was a cross-effect between BR and Me JA.BR was mainly involved in fiber elongation,while Me JA may be involved in the pigment accumulation of brown cotton.Furthermore,certain concentrations of mannitol,Na Cl,KCl,sucrose,Me JA or phenylalanine were advantageous to the brown cotton fiber pigment synthesis.However,neither osmotic regulators,plant growth regulators nor flavonoids biosynthesis precursors caused any significant change to the pigment accumulation of green cotton.