不同生物引发条件对番茄冷胁迫下种子活力和幼苗生理特性的影响

Effects of different bio-priming conditons on tomato seed vigor and seedling physiology characteristics under low temperature stress

  • 摘要: 【目的】探究不同生物引发条件对番茄冷胁迫下种子活力和幼苗生理特性的影响,为番茄的反季节露天栽培提供可行性方案。【方法】以番茄种子种都红运为试验材料,哈茨木霉和荧光假单胞菌作为引发剂,设5个处理:未引发处理(CK);哈茨木霉和荧光假单胞菌的1×107 CFU/m L的孢子液(T1处理)和发酵液(T2处理),1×106 CFU/m L的发酵液(T3处理)及无菌过滤液(T4处理)引发,回干后测定种子萌发指数;幼苗设4℃低温处理,以常温(25℃)为对照,分别测量形态指标和生理指标。【结果】4个引发处理不同程度促进了番茄种子萌发及植株生长,效果显著。通过种子萌发指数发现,引发效果T4>T3>T2>T1,就活力指数而言,分别显著提高90.00%、67.70%、51.30%和50.00%。分析60 d的幼苗形态指标发现,T4处理的株高、茎粗和茎鲜重均达最大值,T2处理的根长和茎鲜重达最大值;分析60 d幼苗的生理指标发现,T2处理的过氧化氢酶(CAT)含量最高。光合色素和可溶性糖含量则依次表现为T4>T3>T2>T1,T4处理的可溶性蛋白和脯氨酸(PRO)含量达最大值,分别显著增加71.74%和46.50%,其他处理的增幅略低于T4处理。4个引发处理的相对电导率(REC)在低温胁迫前后的变化相差不大,CK经低温胁迫后急剧升高。MDA含量在低温胁迫后的增量依次表现为T3>T4>T2>T1。相关分析结果表明,株高、茎粗、茎鲜重与植株CAT含量呈极显著正相关(P<0.01,下同),根鲜重与REC和MDA含量呈极显著负相关,与PRO含量呈极显著正相关。【结论】番茄种子经哈茨木霉和荧光假单胞菌的无菌过滤液等体积混合引发有利于提高种子活力,促进植株生长,增加植株体内的保护酶活性,最终提高番茄植株的低温耐受性。

     

    Abstract: 【Objective】To explore the effects of different bio-priming conditions on seed vigor and seedling physiological characteristics of tomato under low temperature stress,and to provide a feasible scheme for the future out-ofseason open-air cultivation of tomato.【Method】With tomato seed Zhongduhongyun was used as material,Trichoderma harziensis and Pseudomonas fluorescens were used as seed priming agents,and five treatments were set up:which were non-primed treatment(CK),1×107 CFU/m L spore fluid(T1) and fermentation fluid(T2) of T.harziensis and P.fluorescens,1×106 CFU/m L fermentation fluid(T3) and sterile filtrate(T4).The germination index of seed was measured after drying.4℃low temperature treatment was set for seedings,normal condition(25℃)was control,the morphology indexes and physiological indexes were detected.【Result】The four priming treatments promoted seed germination and plant growth in different degrees,and the promotion effect was significant.According to the seed germination index,the priming effect was T4>T3>T2>T1,significantly increased by 90.00%,67.70%,51.30%,50.00%in terms of vitality index,respectively.After 60 d of seedling morphology indexes analysis,it was found that the plant height,stem diameter and stem fresh weight of T4 reached the maximum value,while the root length and stem fresh weight of T2 reached the maximum value.Analysis of physiological indexes of 60 d seedlings showed that the catalase(CAT) content of T2 was the highest.The content of photosynthetic pigment and soluble sugar showed the order of T4>T3>T2>T1,and the contents of soluble protein and proline(PRO) in T4 reached the maximum value,significantly increasing by 71.74%and 46.50%,while the increase of other treatments was slightly lower than that of T4.The relative conductivity(REC) of T1,T2,T3and T4 changed little before and after low temperature stress,while CK increased sharply after low temperature stress.The increment of MDA content after low temperature stress was T3>T4>T2>T1.Correlation analysis showed that plant height,stem diameter and stem fresh weight were extremely significantly positively correlated with plant CAT content(P<0.01,the same below),root fresh weight was extremely significantly negatively correlated with REC and MDA content,and extremely significantly positively correlated with PRO content.【Conclusion】Equal volume mixing sterile filtrate of T.harziensis and P.fluorescens priming tomato seeds can improve seed vitality,promote plant growth,increase the protective enzyme activity in plants,and thus improve the low temperature tolerance of tomato plants.

     

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