Studies On Response Of Piriformospora Indica To Growth Promotion And Stress Resistance Of Zingiber Officinale

In response to the prominent problems that restrict the development of agriculture,landscape and other industries in China,such as the decline of soil organic matter,structural damage,serious diseases and pests,and the lack of excellent strains,this experiment used the establishment of a symbiotic relationship between Piriformospora indica and tissue cultured ginger as a breakthrough point.A combination of tissue cultured ginger pot（Three gradient stresses of 100%potassium nutrient,50%potassium nutrient,and 0%potassium nutrient were applied,with river sand as the cultivation substrate）and greenhouse experiments（Field loam soil with moderate fertility）was used to systematically study the effects of Piriformospora indica on growth,physiological,biochemical and disease resistance of ginger under nutrient stress,and to explore the growth promotion and stress resistance ability of Piriformospora indica on tissue cultured ginger.The main research findings are as follows:（1）The Piriformospora indica can establish a symbiotic relationship with tissue-cultured ginger.The results of the greenhouse experiment showed that all three experimental sections inoculated with Piriformospora indica were infected,with infection rates of 15.74%,12.04%,and 18.52%,respectively.The results of the pot experiment showed that under K nutrient stress,Piriformospora indica could be observed in the root system of potted ginger inoculated with Piriformospora indica,with infection rates of 12.96%,12.04%,and 12.04%,respectively.This indicates that both Piriformospora indica from two different experimental environments can successfully infect and colonize the root system of ginger,indicating that a symbiotic relationship has been established between Piriformospora indica and ginger.（2）Piriformospora indica can promote the growth of tissue-cultured ginger.The height of ginger plants inoculated with Piriformospora indica in the greenhouse increased by 33.80%,the number of tillers increased by 36.28%,and the aboveground and underground biomass increased by 83.79%and 60.43%,respectively.There was a significant difference in growth and biomass compared to the experimental section without inoculation.In pot experiments,inoculation with Piriformospora indica can alleviate the degree of damage to ginger under low potassium conditions and promote the growth of ginger under three K nutrient concentrations.Especially under 50%K nutrient stress,inoculation with Piriformospora indica significantly promoted the growth and biomass of potted ginger,with plant height growth,total fresh weight,and total dry weight increased by 61.79%,57.02%,and 62.80%,respectively,compared to the control group.（3）Piriformospora indica can enhance the resistance of greenhouse ginger to root-knot nematode disease.The results of the greenhouse experiment showed that the disease index of root-knot nematode disease of ginger tissue cultured in a greenhouse inoculated with Piriformospora indica ranged from 24.00%to 44.00%,and that of the uninoculated group ranged from 45.00%to 66.67%.The average disease index of the three test sections of the inoculation group was 40.00%lower than that of the control group,indicating that Piriformospora indica had a certain antagonism against root-knot nematode disease.（4）Piriformospora indica can promote the photosynthesis of potted ginger.The experimental results showed that in the absence of potassium,inoculation with Piriformospora indica can promote the growth of ginger plants by increasing the net photosynthetic rate and water use efficiency of ginger,reducing intercellular CO₂ concentration,and improving the photosynthesis of potted ginger.The promotion effect is most significant under 50%and 0%K nutrient stress.（5）Piriformospora indica can reduce the damage of K deficiency to plants by adjusting the osmotic regulators of potted ginger.The experimental results showed that with the decrease of K nutrient concentration,the content of malonaldehyde in potted ginger showed a downward trend,while the content of soluble protein gradually increased.The content of proline and soluble protein in the inoculated group was always lower than that in the control group.（6）Piriformospora indica can enhance the antioxidant enzyme activity of potted ginger.Research has shown that as the concentration of K nutrient decreases,the SOD and CAT activities of the inoculation group show a trend of first increasing and then decreasing;The SOD activity in the control group showed a gradually increasing trend,while the CAT activity showed a first increasing and then decreasing trend.Under 100%and 50%K nutrient stress,the antioxidant enzyme activity of the inoculated group was higher than that of the control group,and the difference between the inoculated group and the control group was the most significant under 50%K nutrient stress.This indicates that inoculation with Piriformospora indica can improve the host’s stress resistance to some extent by increasing the antioxidant enzyme activity of ginger plants.To sum up,the inoculation of Piriformospora indica can not only enhance the antagonism of greenhouse-grown ginger against root-knot nematode disease but also significantly increase the growth of greenhouse-grown ginger and significantly promote the growth of potted ginger.Through correlation analysis,it can be seen that the fresh weight of potted ginger in the inoculation group is significantly correlated with malonaldehyde content,intercellular CO₂concentration,and water use efficiency,while the fresh weight of potted ginger in the control group is not significantly correlated with malonaldehyde,intercellular CO₂ concentration,and water use efficiency.The results of Two-way ANOVA showed that compared to the control treatment,inoculation with Piriformospora indica significantly increased the net photosynthetic rate and water use efficiency of ginger,and significantly reduced intercellular CO₂ concentration and soluble protein content.This indicates that Piriformospora indica can promote an increase in the fresh weight of potted ginger under nutrient stress by reducing intercellular CO₂concentration and improving water use efficiency.