Effects On Growth,Disease Resistance And Soil Nutrients When Different Species Konjac Species Mixed

For the past few years,as a healthy food,konjac has been known by more and more people.The demand for konjac is increasing thus the planting area in our country is also expanding.However,the high incidence of diseases causes the decline of production.Therefore,it is extremely urgent to investigate the mixed variety cultivation mode among different species of konjac to realise the disease prevention and yield increase.In this paper,Amorphophallus albus128 interbreed base in Guantian village,Shiquan county,Ankang city,Shaanxi province was selected as the experimental location,and three different species of konjac including Amorphophallus konjac,Amorphophallus albus and Amorphophallus albus 128 were mixed planted with the proportion of 1:1,to conduct the research on the effects of interbreed on growth,disease resistance,yield,quality and soil nutrient content,to analyze the effects of root exudates of Amorphophallus albus on the number of pathogenic bacteria and soil microorganisms and to explore the resistance mechanism of different species of Amorphophallus albus,so as to improve the yield and quality of Amorphophallus albus,which is of great significance in improving the long term healthy development of China’s konjac industry.The main research results are as follows:1.When Amorphophallus konjac was mixed with the other two kinds of konjac,the incidence of ill seedling was more serious,and when mixed with Amorphophallus konjac 128,the incidence of ill seedling was the most serious,which was 22.50%.Amorphophallus albus,as a variety with strong disease resistance,had stronger disease resistance in mixed species with Amorphophallus albus,and there was almost no disease incidence and ill seedling during the whole growth period（3.75%）.No apparent variation pattern was found in the incidence and ill seedling of Amorphophallus albus 128 either in mixed species or in single species.2.The nitrogen content of leaves in the head changing period and tuber mature period was higher than that of single species when Amorphophallus konjac was mixed.The nitrogen content of leaves treated by the two mixed species of Amorphophallus albus in the head changing period and tuber expanding period was better than that of single species,and mixed species of Amorphophallus albus with Amorphophallus albus > single species > mixed species with Amorphophallus albus 128 during tuber mature period.Amorphophallus albus 128 had the highest nitrogen content in the leaves of Amorphophallus albus in the head-changing period,and the highest value of single species in the expanding period and mature period.The chlorophyll content was better than that of single species in the head changing period and tuber mature period when Amorphophallus konjac was mixed,and the chlorophyll content of single species was the largest during tuber expanding period.The chlorophyll content of Amorphophallus albus mixed seed treatment was higher than that of single seed in three periods,and the chlorophyll content of Amorphophallus albus mixed seed with Amorphophallus albus128 was the highest in three months.The chlorophyll content of Amorphophallus albus 128 was the largest when mixed with Amorphophallus albus in the head changing period,and the largest when mixed with Amorphophallus albus in the expanding period and mature period.3.The agronomic characters of Amorphophallus konjac in different stages were better than that of single species,and the effect of mixing with Amorphophallus albus was the best: the plant height,petiole length,petiole diameter and split leaf width of Amorphophallus albus konjac were better than that of single species in the head changing stage,and the overall agronomic characters of single species were better in the expanding stage and tuber mature stage.Amorphophallus albus 128 had better single agronomic traits in the head changing and expanding stages,which had better value when mixed with Amorphophallus albus in the mature stage.4.The yield of Amorphophallus konjac mixed seed was better than that of single seed,and the effect was the best when mixed with Amorphophallus konjac.Amorphophallus albus had the best single seed yield.When Amorphophallus albus and Amorphophallus albus 128 were mixed,there was a significant drop in yield.The total weight of corm and rhizome of Amorphophallus albus was only half of CK.It was not suitable for mixed seed system: When Amorphophallus 128 was mixed with Amorphophallus albus,the yield data was significantly increased,higher than that of the mixed seed of Amorphophallus 128 CK and Amorphophallus albus.5.The content of glucomannan（KGM）was higher than CK in the mixed seed of Amorphophallus konjac.The mixed seed of Amorphophallus konjac had the greatest improvement,increased by 2.3%,and had the best quality.The KGM content of Amorphophallus albus was the highest,which was 3.02% lower than CK when mixed with Amorphophallus albus 128.The KGM content of Amorphophallus albus 128 mixed with Amorphophallus albus was the highest,and that of Amorphophallus albus mixed with Amorphophallus albus was the lowest,with a difference of 2.48%.6.With the planting of Amorphophallus konjac,the organic matter,available phosphorus,ammonium nitrogen and available potassium in the soil showed a decreasing trend in the whole growth period.Among them,the organic matter,available phosphorus and available potassium in mixed species decreased faster,and the p H changed irregularly between different plants.7.The root exudates of three species of Amorphophallus konjac had inhibitory effect on pathogenic bacteria at high concentrations.The inhibitory effect was proportional to the concentration of root exudates.The higher the concentration,the better the inhibitory effect of root exudates.The root exudates of Amorphophallus albus and Amorphophallus albus 128 with better resistance had stronger inhibitory effects,while those of Amorphophallus albus species susceptible to diseases had weaker inhibitory effects.8.The number of bacteria in the soil of resistant species of Amorphophallus albus and Amorphophallus albus 128 was significantly less than that of Amorphophallus albus and three mixed species in the swelling and harvest periods.No obvious difference was found in the number of soil fungi among different species,but the number of mixed species was significantly greater than that of three single species in the expansion period and harvest period.The number of soil actinomycetes had no significant difference among species and treatments at the same time.