巨大芽孢杆菌菌剂对苹果产量、品质及土壤微生物的影响

Effects of Bacillus megaterium on Yield,Quality and Soil Microorganism of Apple

以树龄16年‘红富士’苹果(Malus×domestica)为试材,研究巨大芽孢杆菌(Bacillus megaterium)菌剂处理对新梢生长、果实产量和品质以及土壤微生物数量、微生物群落结构和土壤养分的影响。结果表明,与对照相比,2021、2022连续两年苹果树春季施用巨大芽孢杆菌菌剂,30 d内新梢增长率分别提高了3.45%和17.01%,60 d内新梢增长率分别提高了2.58%和6.71%;产量分别增长了7.17%和7.01%;而对果形指数、硬度、可溶性糖含量、可溶性固形物和维生素C含量等指标均无显著影响。2021年处理组单株果实数量增加4.95%。2022年处理组的果实着色相关指标红绿色度a*低于对照,色度角h高于对照,而2021年无显著差异。施用菌剂后0~20 cm、20~40 cm土层真菌数量减少,细菌增加,但随着时间延长,菌剂效果逐渐减弱;真菌和细菌群落的α多样性无显著变化;土壤真菌中短梗蠕孢属(Trichocladium)、产油菌属(Solicoccozyma)、担子菌酵母属(Naganishia)和土赤壳属(Ilyonectria)相对丰度分别是对照的1.87倍、1.92倍、2.91和3.38倍;陶氏菌属(Tausonia)和头束菌属(Cephalotrichum)相对丰度分别是对照的76.44%和67.96%;土壤细菌中链霉菌属(Streptomyces)和芽单胞菌属(Gemmatimonas)相对丰度分别是对照的2.65倍和1.33倍;而朱氏杆菌属(Chujaibacter)的相对丰度是对照的48.88%;处理苹果根际土壤中细菌和真菌OTU数量与对照相比发生显著变化;苹果根系土壤的速效磷、速效钾含量分别比对照高21.87%和20.81%、5.14%和5.31%。综上,春季施用巨大芽孢杆菌菌剂能够抑制土壤有害真菌,改善土壤微生物群落结构和数量,活化土壤磷、钾,促进苹果生长,提高苹果产量。

In order to clarify the effects of Bacillus megaterium on the growth of apple(Malus×domestica)trees and the ecological effects of the soil,a field experiment was conducted to explore the effects of B.megaterium application on the growth of new branches,the yield and quality of apple fruits,and the characteristics of soil microbial community using 16 years-old‘Red Fuji’apple trees.The results showed that the growth rate of new branches in 2021 and 2022 were increased by 3.45%and 17.01%within compared with the control 30 d,respectively(P<0.05),and by 2.58%and 6.71%within 60 d,respectively(P<0.05),after application of B.megaterium inoculant to apple trees in spring.Moreover,the yield increased by 7.17%and 7.01%respectively(P<0.05);the fruits number per plant were increased by 4.95%in 2021(P<0.05),in the treatment group of 2021 and 2022,but application of B.megaterium inoculant had no significant effect on the fruit shape index,hardness of fruits,and the contents of soluble sugar,soluble solids,and vitamin C in apple fruits.In 2022,the fruit color related indexes of the treatment group,Red-Green Index a*is lower and Chroma angle h is higher than those of the control group,and there were no significant differences in 2021.Furthermore,the number of fungi in the soil layer of 0–20 cm and 20–40 cm decreased,while the number of bacteria showed the opposite trend.There was no significant difference inα-diversity of soil fungal and bacterial communities in the soil layer of 20–40 cm.For the soil fungal community at genus level,the relative abundances of Trichocladium,Solicocozyma,Naganishia and Ilyoctria in the treatment 1.87,1.92,2.91 and 3.38 times higher than those in the control;The relative abundances of Tausonia and Cephalotrichum were 76.44%and 67.96%of that in the control,respectively(P<0.05).For the soil bacterial community at genus level,the relative abundances of Streptomyces and Gemmatimonas in the treatment were 2.65-and 1.33-fold of that in the control,but the relative abundance of Chujaibacter was 48.88%lower than that of the control(P<0.05).The number of bacteria and fungi OTU in the rhizosphere of the treatment changed significantly compared with the control;Additionally,the contents of soil available phosphorus and potassium in the rhizosphere of the treatment were 21.87%and 20.81%;5.14%and 5.31%,respectively(P<0.05),which are higher than those in the control(P<0.05).In summary,the application of B.megaterium inoculant to apple trees in spring can inhibit harmful soil fungi,improve the structure and quantity of soil microbial community,mobilize soil phosphorus and potassium,and promote the growth of apple tree and apple fruits yield.