Seed Output From Viola Philippica CH-CL And Its Effect On The Life History Traits Of Offspring

Viola philippica,belonging to the Viola family(Violaceae),is a perennial low herbaceous plant widely distributed around the world.It has a unique mixed dimorphic breeding system.Chasmogamous flowers(CH)are generally produced in early spring,while Cleistogamous flowers(CL)are present in late spring to late autumn.This dimorphic mixed breeding system is a good test material to study plant reproduction strategy.In this study,we investigated the reproductive phenology,fruiting pattern,seed export and effects on the life history of offspring of V.philippica.Elucidating the relationship between the life history characteristics of plants formed by CH seeds and CL seeds and the fitness of their progeny,and revealing the evolutionary significance of CH seeds and CL seeds,the results will provide an in-depth understanding of the reproductive strategies of bimorph plants with this mixed breeding system and its progeny fitness.The study of life history evolution helps.The main results are as follows.(1)The same plant of V.philippica produces two different forms of flowers,CH flowers from mid-April to late April,with a short,concentrated and abundant flowering period,showing a concentrated flowering pattern,and CL flowers from late April to late October,showing a continuous flowering pattern.The fruit of CH flower of V.philippica begin to ripen and disperse at the end of April.the CL flowering fruit continue to bear and disperse from mid-May to early November.the number of the seed of CL flower is greater than the number of the seed of CH flower.(2)The germination characteristics of the two types of seeds of V.philippica are different,and both types of seeds can germinate at PEG concentrations from 0 to 25%.However,the seed of CH flower had the advantage of more drought-tolerant germination than the seed of CL flower.With the increase of burial depth,the germination of both seeds was the first to increase and then decrease,and the emergence ability of the seed of CH flower was stronger than that of CL flower.(3)Both seed-derived progeny of V.philippica produced only CL flowers and CL fruits in the first year of their growing season.CL flowers of CH seed-derived progeny lasted from mid-June to late October,and CL flowers of CL seed-derived progeny lasted from late June to late October.The germinated progeny of CH seeds of V.philippica were superior to the germinated progeny of CL seeds in terms of plant size and reproduction.The total biomass,root biomass and fruit biomass of CH seed germination plants were significantly larger than those of CL seed germination plants.In summary,the results indicate that V.philippica produces differential seeds through a dimorphic breeding system,which maximizes the fitness of plants in heterogeneous environments.CH flowering progeny have higher viability and reproductive capacity,which can increase the genetic diversity of the population.While CL flowers produce more seeds,it can produce more seeds to maintain the plant population size.