Classification and phylogenetic analysis of Chinese hawthorn assessed by plant and pollen morphology.

The Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.) is uniquely originated in northern China. The ecological and horticultural importance of Chinese hawthorn is considerable and some varieties are valued for their fruit or medicine extracts. Its taxonomy and phylogeny remain poorly understood. Apart from general plant morphological traits, pollen is an important trait for the classification of plants and their evolutionary origin. However, few studies have investigated the pollen of Chinese hawthorn. Here, an analysis of plant and pollen morphological characteristics was conducted in 57 cultivars from the Shenyang region. Thirty plant morphological characters and nine pollen grain characters were investigated. The plant morphological analysis revealed that the coefficient of variation for 13 traits was >20%, which indicates a high degree of variability. We also found that the pollen grains varied greatly in size, shape (from prolate to perprolate), and exine pattern (striate-perforate predominantly). The number of apertures was typically three. Based on these findings, we suggest that pollen morphology associated with plant morphological traits can be used for classification and phylogenetic analysis of Chinese hawthorn cultivars. In sum, our results provide new insights and constitute a scientific basis for future studies on the classification and evolution of Chinese hawthorn.

Genetic variability and diversity of the main resources of lily assessed via phenotypic characters, pollen morphology, and ISSR markers.

Lily (Lilium spp), which belongs to Lilium, is one kind of monocotyledon. As a perennial ornamental plant with extremely high esthetic, edible, and medicinal value, lily has gained much favor due to its mostly showy flowers of various colors and elegant shape. In this research, we studied experimental materials in a sample of 49 individuals including 40 cultivars, nine species of wild lily, and their variants. The collection of 40 cultivars covered all six hybrids in the genus, i.e., Asiatic hybrids, Oriental hybrids, Longiflorum hybrids, LA hybrids, LO hybrids, and OT hybrids. Genetic diversity and inter-relationships were assessed through analysis of phenotypic characteristics, pollen morphology, and ISSR molecular markers. Quantitative characters were selected to analyze phenotypic variation, with results indicating greater variability in petiole length as compared to other characters. Pollen morphological observations suggested that the largest variation coefficient between all hybrids and wild species was the lumina. ISSR makers demonstrated that both cultivars and wild species possess a high level of genetic diversity. Specifically, the genetic diversity of wild lily was higher than cultivars.