Ultraviolet Mutagenesis Of Spores And Breeding Of New Hybrid Strains In Morchella

Morels(Morchella spp.)is a world-wide prized edible and medicinal fungi which is highly appreciated by consumers for its pleasant,tender,unique flavor and taste.The cultivating industry of morels has developed rapidly in recent years,which has brought considerable benefits to the majority of growers.However,there are problems in morel cultivation,such as poor adaptability to high temperature and disease resistance.The disease is particularly serious in spring fruiting stage of protected cultivation in northern China,which makes serious declines of quality and yield common problems,restricting further development of morel cultivating industry.At present,the main cultivars of morel in China are homogeneous.It is urgent to select and breed excellent cultivars with high temperature and disease resistance,which are suitable for protected cultivation in northern China.In this study,the breeding methods of ultraviolet mutagenesis and single spore hybridization were used to identify the fruiting of hybrid progeny strains by mating molecular markers detection technique.In order to enrich morel germplasm resources and provide theoretical basis for morel breeding,excellent strains were screened comprehensively by comparing the high temperature and Fusarium solani resistance of hybrid progeny strains at mycelium stage,and combining the determination of yield,commercial characters and resistances in fruiting stage,The main results are as follows:1.The ascospores were collected by suspension method and spore suspensions were repared for gradient dilution,and the optimum dilution multiple of spore suspensions was 105 times.UV irradiation treatment was set with different duration,and the lethality rate was counted.The best duration of UV mutagenesis irradiation was 40 s.2.A total of 87 single spore germinating strains were obtained by UV irradiation.7 single spore germinating strains with MAT1-1-1 mating type gene and 50 single spore germinating strains with MAT 1-2-1 mating type gene were identified by MAT mating type gene molecular marker.350 hybrid strains were obtained by pairing hybridization,and 192 UV-mutated hybrid strains with both mating type genes of MAT1-1-1 and MAT1-2-1 were identified by mating type gene molecular markers.3.147 effectively mutated hybrid mutagenesis progenies were identified by antagonistic test.The lethal temperature of parents was determined to be 38℃ by high temperature culture.41 UV mutated progeny strains with strong resistances to high temperature and disease were obtained by comparing the growth of hypha and disease resistance,when the mutant hybrid strains treated were with 38℃ and above high temperature gradient,and cultivated at 25℃ for recovery then.4.The mycelial growth of parents and UV mutated 41 hybrid strains in mycelium stage,yield,fruiting body shape,production cycle,other agronomic characters,growth and disease resistance in the fruiting body stage were comprehensively compared and analyzed.92 and 292 were screened as the target UV mutated strains,which showed better performance in fruiting body shape and commercial traits,such as shorter production cycle,higher yield and stronger disease resistance.Among them,292 had the best performance with the highest total yield of 4.32kg,and the yield per unit area was 0.86 kg.m-2,which was 33.3%higher than that of the parent.The ratio of pileus and stipe length was better than that of the parent,with good fruiting body shape.The single fruiting body weight was 22.32 g,and the production cycle was 51 d,5 d shorter than that of the parent.The disease resistance was better than the parent;92 also had relatively good fruiting body shape.The total yield was 4.05 kg,and the yield per unit area was 0.81 kg.m-2,which was 25%higher than that of the parent.The production cycle was 53 d,which was 3 days earlier than that of the parent,and the disease resistance was better than that of the parent.