壳寡糖浸种对低温下江西铅山红芽芋脱毒试管芋萌发及生理代谢的影响

    Effects of chitosan oligosaccharide soaking on germination and physiological metabolism of virus-free test tube taro from Jiangxi Yanshan red bud taro at low temperature

    • 摘要: 江西铅山红芽芋脱毒试管芋一般在1月至2月上旬晴天播种,“倒春寒”等低温胁迫会导致早播的江西铅山红芽芋脱毒试管芋生长缓慢,出苗周期变长,严重时会造成烂种死亡,出苗率降低,影响其产量。为提高播种期江西铅山红芽芋脱毒试管芋抗寒性,该研究利用植物组织培养和植物生理学的方法测定了壳寡糖浸种后低温下江西铅山红芽芋脱毒试管芋的萌发及其相关生理指标。结果表明:200~250 mg/L壳寡糖浸种可显著促进低温下江西铅山红芽芋脱毒试管芋的萌发。与低温对照相比,当浸种浓度为200 mg/L时,在内源激素方面,有利于低温下江西铅山红芽芋脱毒试管芋萌发过程中赤霉素、玉米素核苷、多胺和茉莉酸的积累,而不利于生长素和脱落酸的积累;在抗氧化方面,提高了超氧化物歧化酶、过氧化物酶、过氧化氢酶的活性,降低了丙二醛和过氧化氢的含量;在渗透调节方面,有利于可溶性糖、可溶性蛋白、脯氨酸的积累;在代谢关键酶方面,可提高脂肪酶、蛋白酶和α-淀粉酶活性以及三磷酸腺苷含量。因此,200 mg/L壳寡糖可以调控低温下江西铅山红芽芋脱毒试管芋内源植物激素和渗透调节物质含量、抗氧化酶和代谢关键酶活性,促进其在低温下的萌发。

       

      Abstract: Jiangxi Yanshan red bud taro is one of national geographical indication agricultural products from Yanshan County, Jiangxi Province, China. This type of vegetable is generally propagated asexually through corms. Such long-term cultivation can easily lead to virus accumulation and species degeneration. Cultivation of red bud taro virus-free plantlets can restore its species, enhance its growth potential and disease resistance, and significantly increase its yield and quality. However, some challenges are still remained on the large-scale cultivation in the virus-free seedlings of Jiangxi Yanshan red bud taro, such as relatively weak virus-free seedlings, low survival rates of transplantation and domestication, difficulty in long-distance transportation and cultivation, as well as the long-distance exchange of germplasm. Alternatively, virus-free test tube taro can serve as the virus-free seedlings, due to the stronger stress resistance, easy conservation, convenient transportation, and germplasm exchange. Virus-free test tube taro of Jiangxi Yanshan red bud taro can be produced year-round and can achieve industrial production. Virus-free test tube taro of Jiangxi Yanshan red bud taro is generally sown on sunny days from January to early February. Low temperature can limit its germination, and low temperature stress such as "late spring cold" can cause early sown virus-free test tube taro to grow slowly, have a longer emergence cycle, and in severe cases, cause virus-free test tube taro die, resulting in a lower emergence rate and affecting its yield. This study aims to improve the cold resistance of virus-free test tube taro of Jiangxi Yanshan red bud taro in the sowing period. Plant tissue culture and plant physiology were used to determine the germination and physiological indexes of virus-free test tube taro of Jiangxi Yanshan red bud taro under low temperature after soaking with chitosan oligosaccharides. The results showed that the soaking seeds with 200-250 mg/L chitosan oligosaccharide were significantly promoted the germination of virus-free test tube taro of Jiangxi Yanshan red bud taro under low temperature. When the soaking concentration of chitosan oligosaccharide was 200 mg/L, there was the better accumulation of gibberellin (GA3), ribosylzeatin (ZR), polyamines (PA), and jasmonic acid (JA), whereas, the less accumulation was observed in the auxin (IAA) and abscisic acid (ABA) in terms of endogenous hormones. In terms of antioxidation, 200 mg/L chitosan oligosaccharide could increase in the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), whereas reduce the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2). In terms of osmotic regulation, there was the better accumulation of soluble sugars (SS), soluble proteins (SP) and proline (Pro) when the soaking concentration of chitosan oligosaccharide was 200 mg/L. In terms of metabolic key enzymes, 200 mg/L chitosan oligosaccharide could increase the activity of lipase (LIP), protease (PR) and α- Amylase (ɑ-AMS) and the content of adenosine triphosphate (ATP) . Therefore, 200 mg/L chitooligosaccharide could regulate the content of endogenous plant hormone and osmoregulation substances, as well as the activities of antioxidant enzymes and key metabolic enzymes in the virus-free test tube taro of Jiangxi Yanshan red bud taro at low temperature, and promote its germination. The finding could provide a strong reference for the cold tolerance of virus-free test tube taro from Jiangxi Yanshan red bud taro. It was of great significance for the early spring cold sowing, taro seed germination, and high-yield harvest of Jiangxi Yanshan red bud taro.

       

    /

    返回文章
    返回