Study On Key Techniques Of Tomato Tissue Culture Seedling Grafting

In this experiment,‘Maofen 812’and‘Zhegan No.1’were used as experimental materials.Through tissue culture and grafting experiments,the influencing factors in tomato tissue culture regeneration system were systematically and comprehensively discussed,such as seed germination methods,external The selection of the plant,the factors affecting the light,etc.,and optimize a set of tomato rapid propagation system.The excellent rootstock was used to graft the scion that was rapidly propagating,and the grafting methods and survival rate of tomato plants were studied.This experiment not only perfected the tomato regeneration system,but also further utilized grafting,which opened a new way of thinking for factory seedlings.Experimental results show that:1.‘Maofen 812’variety tomato is the experimental material.The tomato rapid propagation system is studied by studying the relevant factors that affect the in vitro regeneration system of tomato cotyledons and hypocotyls.The best method for aseptic tomato seedlings is to soak the seeds in low-temperature sterile water for 12 hours,sterilize them with 75%ethanol for 5 minutes,and put them in 15%sodium hypochlorite for 15 minutes.After 3d of dark cultivation,the germination days are 4d and the germination potential is 95.3%,and then transfer After culturing under light conditions,sterile seedlings can be obtained within 5-6d.Compared with aseptic seedlings that obtained the same growth situation 3d in advance without dark cultivation.2.The best induction medium is:MS+1.0 mg·L^-16-BA+0.2 mg·L^-1IAA,the recovery rate is 97.33%;the best proliferation medium is:MS+2.0 mg·L^-16-BA+0.2 mg·L^-1IAA;The best rooting medium is:MS+2 mg·L^-1IAA.3.The cotyledons are the best explants for inducing adventitious buds of tomatoes,and placing the back side up on the medium is more conducive to the induction of adventitious buds.One callus multiplier is 4.0,and one seed can multiply 32 complete plants.4.Optimized the tomato rapid propagation system and studied from the time of seedling growth and the cost of seedling growth.According to statistics,it takes 9d to produce sterile seedlings from seeds,30d to induce callus and adventitious buds,and 10d to adventitious buds.The seedlings can be refined after 10d of rooting.The seedlings are transplanted in the greenhouse 2d later for grafting.61d from seed to transplanting greenhouse effectively shortened the tissue culture cycle.5.The mechanism and metabolic pathways of exogenous hormones to promote callus formation and adventitious bud induction were discussed.The callus in the two groups of mediums,which selected the best adventitious buds No.Ⅴand worstⅠ,was selected from nine groups Tissue,to determine the content of four endogenous hormones:auxin（IAA）,gibberellin（GA）,cytokinin（CTK）and abscisic acid（ABA）.Among them,the cotyledons were used to induce callus and adventitious buds,and the content of auxin IAA and gibberellin GA of callus gradually increased,and reached the peak when the callus expanded and stabilized at 20d,and then decreased;The cytokinin CTK gradually decreased,rebounded at 10d,and gradually fell after reaching the peak at 20d;abscisic acid ABA gradually decreased with the formation of callus,and increased after 10d of callus growth.During the induction process using hypocotyls,it was found that the contents of auxin IAA and gibberellin GA reached a peak at 10d,which was earlier than that of cotyledons by 10d;the cytokinin CTK gradually decreased and rebounded to the peak after 10d.Gradually decreased;ABA decreased gradually with the formation of callus,and increased after the adventitious shoots of callus.Comparing the test results,it was initially found that gibberellin GA and auxin IAA had a positive effect,and auxin IAA and ABA had an antagonistic effect.With the growth of auxin IAA,the content of ABA decreased.