Genomic Size And Phenotype Analysis Of Evergreen Broad-leaved Forest Species In Huangshan Mountain

In this thesis,the genome size of 30 species of evergreen broad-leaved forest in Huangshan was determined by flow cytometry,and the experimental process was explored and optimized.The genome sizes of 30 tree species were reported for the first time.The leaf and reproductive phenotypic traits of these tree species were characterized by various experimental methods.The correlation between genome size and phenotypic traits was analyzed.The main results are as follows:(1)The DNA-C values of 30 species measured in this study ranged from 0.625 pg(Elaeagnus pungens)to 1.907 pg(Adinandra millettii).These data are all unrecorded in the global database and belong to the newly added.Most of the genomes of 30 tree species belong to the first grade "very small"(C-value < 1.4 pg).The trend of variation among different tree species was shrub < small tree < tree,as well as evergreen tree < deciduous tree.(2)Highly markedly,the stomatal size of leaves was negatively correlated with stomatal density,while positively correlated with epidermal cell size.Stomatal density was negatively correlated with epidermal cell size to a significantly remarkable degree,and it was lower in evergreen trees than in deciduous trees.The average value for leaf nitrogen content was 16.69mg/g,phosphorus content 0.75 mg/g,and potassium content 13.3 mg/g,while the average specific leaf area was 106.27 cm~2/g.(3)The Julian daily distribution pattern of flowering and fruiting period is as follows:flowering period was mainly within 90-180 days,while fruiting period was mostly within270-365 days.Seeds of most tree species were close to spherical shape,and the variation range of seed weight reached three orders of magnitude.Most tree species produced small and medium seeds.The seeds of evergreen plants were larger than those of deciduous plants.Trees had the largest seeds,followed by small trees,and shrub seeds was the smallest.The seeds of nuts or drupes were relatively larger.(4)The correlation analysis between genome size and phenotypic traits showed that genome size was positively correlated with epidermal cell size,while negatively correlated with epidermal cell density.There was a significant negative correlation between genome size and seed morphological index(mean variance of three-dimensional seed size),which indicated that with the increase of genome size,the seeds inclined to spherical shape.No significant correlation was found between genome size and seed size,which may be due to the complexity of development and the diversity of nutrient structure.The genome size was not significantly correlated with fruit type,flowering period,and specific leaf area,respectively.Genome size was positively correlated with nitrogen content in plant leaves,while not with phosphorus and potassium contents.Through the analysis of the results,we can deeply understand the genetic variation and ecological adaptability of various tree species and the formation and maintenance mechanism of forest biodiversity.And it can also provide basic data for the introduction and domestication of some tree species and for the protection and utilization of planting resources.It will establish the scientific basis for monitoring,management,and protection of forest biodiversity of evergreen broad-leaved forest in Huangshan Mountains.