Two chemical mutagens modulate the seed germination,growth,and phenotypic characteristics of Chinese fir(Cunninghamia lanceolata)

Chinese fir(Cunninghamia lanceolata(Lamb.)Hook),a fast-growing and economically important timber tree species in China,is widely used in construction,furniture,and paper manufacture but has a long breeding cycle.Chemical mutagens,such as ethyl methane sulfonate(EMS)and sodium azide(SA),are widely used in crops such as rice,wheat,cotton,soybean and sugarcane but their utility for tree breeding is unknown.In this study we examined the effects of EMS and S A on Chinese fir seed germination and growth.Chinese fir seeds were treated with the two chemical mutagens;were planted in Jiangle County,Fujian Province,China;and their heights were measured from 2011 to2017.The concentrations and durations of treatment with the two chemical mutagens were significantly associated with the Chinese fir seedling and mortality rates,as well as with the heights of trees from the seedling stage to 3 years old.We also generated 127 mutants with abnormal branches and reproductive growth.We report here the effects of two chemical mutagens on Chinese fir breeding;our data will contribute to knowledge of the utility of EMS and SA in forestry.

Ethyl Methanesulfonate as Inductor of Somaclonal Variants in Different Crops

Ethyl methanesulfonate is a chemical mutagen,which is currently being used in plant breeding,to increase genetic variability in genes of agronomic interest,of species useful in agriculture.It primarily causes single base point mutations by inducing guanine alkylation,resulting in GC to AT transitions.Its effect is different between clones of a genotype and between genotypes of the same species.This review presents the results obtained in recent research,where its effect on plant tissues,callus,and cells in suspension has been evaluated.Changes in the phenotypic expression of somaclonal variants were reported,involving morphology,production of secondary metabolites,changes in metabolic routes of resistance,tolerance to stress,increased seed yield,among others.In addition,this review compiles the doses and guidelines to consider before using this mutagen,which can serve as a guide for future trials in deciding the response variables,the type of plant explants and the selection of the study model.Mutant lines have allowed plant breeders to have a collection of plants with different characteristics,in places where the cultivar does not have its center of origin.It is important to note that it is still necessary to continue evaluating the heritability of mutations and their behaviour in the environment where they will be established,in order to obtain new varieties of plants that can be cultivated with uniformity in their genetic response.

Establishment of Rapid Propagation System for Saponaria officinalis L. Progeny After EMS Mutation

Saponaria officinalis L. seeds were treated with different concentrations of chemical mutagen to determine the impact of media with various hormone concentrations on the induction of mutated （Saponaria officinalis L.） seeds＇ adventitious buds and rooting culture by using tissue culture technology. The results indicated that the optimum concentration of the chemical mutagen-EMS was 0.3%; the optimum induction medium was MS＋6-BA 1.5 mg · L^-1, NAA 0.1 mg · L^-1 and the optimum rooting medium was MS＋0.05 mg · L^-1 NAA.