Research On The Control Technology Of Tomato Botrytis Cinerea With Water Regulation As The Core

The occurrence of plant diseases is the result of the interaction between the host plant,pathogen and environment,and environmental factors can affect the interaction of plant and pathogen.In order to explore the influence of air humidity,soil moisture and light quality on the growth and development of tomato plants infected by Botrytis cinerea,and to provide a theoretical basis for the environmental regulation and control of tomato gray mold in facilities.In this study,‘Jin peng 14-6’tomato was used as the material,and the experiments were carried out in three parts:air humidity,air humidity and soil moisture coupling,and air humidity and photo-selective network coupling.The effects of environmental factor treatments on the phenotypic changes,cytological differences,tissue structure changes,antioxidant systems,chlorophyll fluorescence parameters,gas exchange parameters,fruit yield and quality of tomato leaves infected with Botrytis cinerea were observed and analyzed.The main research results are as follows:（1）Effects of different air humidity（high air humidity:80%～95%;low air humidity:65%～80%）on Botrytis cinerea infestation on tomatoes.The results showed that a large number of bud tubes elongated in the leaf epidermal cells and differentiated hyphae after 60 hours of high humidity inoculation,and a large number of hyphae were distributed in the mesophyll intercellular space accompanied by disease spots.Botrytis cinerea completes infection in 60h.After 108 hours of low-humidity inoculation,the bud tube elongated and appeared in the epidermis of the leaves and differentiated into hyphae.There was a small number of hyphae in the mesophyll intercellular space,and no obvious lesions appeared.With the infestation of B.cinerea,compared with high humidity,the palisade tissue and sponge tissue structure changed from neat and compact to loosely arranged time lag;the leaf thickness,palisade tissue and sponge tissue thickness at low and high humidity increased initially,followed by a decreasing trend.The leaf tissue thickness after low humidity treatment at the later stage of infection was significantly higher than that of the high-humidity.With progression of the inoculation time,the active oxygen content and antioxidant enzyme activity in high humidity and low humidity were in a relatively active adjustment and adaptation process,which roughly increased at first and then decreased,while there was no significant difference between the control and the inoculation.The trend of change was maintained at the basic amplitude.（2）Effects of air and soil moisture coupling on Botrytis cinerea infestation on tomatoes.The study set up two air humidity（a）levels（high humidity Ha:80%～95%;low humidity La:65%～80%）;three soil moisture（s）levels（low water Ls:60%～70%;middle water Ms:70%～80%;high water Hs:80%～90%）,a total of 6 treatments.The results showed that H_atreatment had earlier onset,serious onset and faster disease progression than L_a treatment.The incidence degree under H_acondition was:H_s>M_s>L_s;Compared with H_s and L_s,the disease progression of M_s was slower under L_a conditions.In the early stage of infection,the thickness of each leaf tissue structure showed an upward trend with the increase of soil moisture under high and low humidity conditions,declining trend in late stage of infection.The content of reactive oxygen species and the activity of antioxidant enzymes were in a relatively active process of adjustment and adaptation with the infection of Botrytis cinerea.（3）Effects of air humidity coupled with photo-selective nets on Botrytis cinerea infestation on tomatoes.The study set up two air humidity levels（high humidity H:80%～95%;low humidity L:65%～80%）;four photo-selective net levels（red shade net R;blue shade net B;black shade net D;no shade net CK）,a total of 8 treatments.The results showed that with the prolongation of the time of inoculation of Botrytis cinerea,the onset was earlier,the onset was more serious and the disease progressed faster under the high humidity treatment than under the low humidity treatment.The disease degree of plants under the photo-selective net treatment under the two air humidity conditions was as follows:D>CK>B>R.With the infestation of Botrytis cinerea,the leaf thickness of 1 dpi～3 dpi（except the control）was H>L,and the leaf thickness of 7 dpi～15 dpi was decreased.Under photoselective net treatment,the net photosynthetic rate（An）and stomatal limit（Ls）of tomato plants were H<L,while the intercellular CO₂ concentration（Ci）was H>L.The decrease of An caused by Botrytis cinerea infection on tomato leaves under high air humidity was mainly caused by non-stomatal restriction.The Fv/Fm（maximum photochemical efficiency）,ΦPSII（actual photochemical efficiency）,and q P（photochemical quenching coefficient）of high humidity were significantly lower than those of low humidity,while NPQ（non-photochemical quenching coefficient）showed H>L,red and blue sunshade net alleviated the decrease of the maximum photochemical efficiency of PSII caused by Botrytis cinerea infection to a certain extent,and the LR treatment had the best effect.The effect of each factor treatment on the yield was expressed as air humidity>photoselective network>the interaction between the two,the yield of LR was the highest,and the yield of HD was the lowestThe research results showed that the environmental conditions for the occurrence of Botrytis cinerea were humidity 80%-95%and infection completion time of 60 hours;The infection completion time of high air humidity and soil high water,low air humidity and soil water conditions was 3 d and 10 d,respectively;The infestation time of high air humidity and black net,low air humidity and red net was 3 d and 15 d,respectively.Low air humidity and medium soil humidity,low air humidity and red shade net inhibited the infection of Botrytis cinerea to a certain extent,delayed the onset time,reduced the onset degree,improved the photosynthetic capacity of the plant,and reduced the impact of the disease on tomato fruit quality and yield.