尖孢镰孢菌对抗病和感病黄瓜幼苗生长及叶片游离氨基酸的影响

为明确黄瓜对尖孢镰孢菌的抗性机理,选择黄瓜抗病和感病材料进行尖孢镰孢菌接种,以接种灭菌水为对照,分析接种后抗病和感病材料的生物学性状及叶片游离氨基酸的动态变化规律差异。结果显示:①接种后20 d,抗病材料的株高、茎粗、叶面积、总根长、根总面积、根总体积、根冠比、壮苗指数与对照差异不显著;而在感病材料中表现为染菌处理显著低于对照,其中总根长表现最为明显,较对照减少51.02%。②接种病原菌后,抗病材料游离氨基酸呈下降趋势,感病材料游离氨基酸呈上升趋势。接种病原菌后8、12、16、20d,抗病材料游离氨基酸总量几乎不受病原菌的影响,感病材料的游离氨基酸总量分别较对照增加14.05%、32.54%、56.29%、149.10%。③在测定的34种游离氨基酸中,有16种在抗病和感病材料中的变化规律明显不同。瓜氨酸和丙氨酸在抗病材料中表现为染菌处理小于对照或与对照差异不显著,而在感病材料中表现为染菌处理大于对照;酪氨酸、牛磺酸、蛋氨酸、亮氨酸、β氨基异丁酸、鸟氨酸、赖氨酸和脯氨酸的表现则相反。接种后随着幼苗生长,瓜氨酸、天冬酰胺、磷酸丝氨酸、尿素、β丙氨酸、组氨酸、鸟氨酸和精氨酸含量在抗病材料中呈下降趋势,而在感病材料中呈上升趋势。推测瓜氨酸、丙氨酸、天冬酰胺、磷酸丝氨酸、尿素、β丙氨酸、组氨酸和精氨酸为促菌氨基酸,酪氨酸、牛磺酸、蛋氨酸、亮氨酸、β氨基异丁酸、赖氨酸和脯氨酸为抑菌氨基酸。上述结果为黄瓜抗枯萎病育种提供参考依据和理论背景。

Effect of Inoculating Fusarium oxysporum on Seedings Growth and Leaf Free Amino Acids of Resistant and Susceptible Cucumbers

In order to clarify the cucumber resistant mechanism to Fusarium oxysporum, this paper inoculated F. oxysporum to both resistant and susceptible cucumber materials taking inoculated sterile water as the control, and analyzed the differences in biological characteristics of the resistant and susceptible materials after inoculation, and dynamic variation rule of free amono acids in leaves. The results showed that: ① At 20 d after inoculation, the plant height, stem width, leaf area, total root length, total root area, total root volume, ratio of root to cap, healthy seedling index of the resistant materials had non-significant differences with those of the control. But in susceptible materials, those index were remarkably lower than those of the control. Among them, the total root length was the most obvious, which in susceptible materials was reduced 51.02% than that of the control. ② After inoculated F. oxysporum, the total free amino acid of resistant material decreased, while that in susceptible material inceased, showing a rising trend. At 8, 12, 16 and 20 d after inoculation, the total free amino acid content of resistant materials was almost not affected by F. oxysporum. While, those of susceptible materials increased by 14.05%, 32.54%, 56.29% and 149.10%, respectively. ③ Among the tested 34 free amino acids, 16 had remarkable different variation rules between resistant and susceptible materials. Citruline and alanine in resistant materials after inoculation were less than or equal to those of the control. But in susceptible materials, they were more than those of the control. The contents of tyrosine, taurine, methionine, leucine, β-aminoisobutyric, ornithine, lysine and proline were the opposite. With seedling growth after inoculation, the contents of citruline, asparagine, phosphoserine, urea, β-alanine, histidine, ornithine and arginine in resistant materals showed a downtrend, but those in susceptible materials showed uptrend. It was speculated that citrulline, alanine, asparagine, serine phosphate, urea, β-alanine, histidine and arginine were bacterial promoting amino acids; tyrosine, taurine, methionine, leucine, β-aminoisobutyric acid, lysine and proline were bacteriostat amino acids. These results provided reference frame and theoretical basis for cucumber resistant breeding to F. oxysporum.