Reproductive Ecology Of The Distylous Persicaria Criopolitana(Polygonaceae)

Persicaria criopolitana(Hance)Migo is a perennial distyly herbaceous plant within the family Persicaria Mill of Polygonaceae.Every autumn and winter season,Poyang Lake grassland will become the flower sea of Persicaria criopolitana,which is a beautiful scenery line.This study used a combination of field experiment and laboratory research to carry out reproductive biology research on Persicaria criopolitana in Poyang Lake area.To provide a reasonable basis for its rational introduction,find a suitable introduction method.The research results are as follows:1.Type 2 style and accessory signs of Persicaria criopolitanaThe statistical analysis of the stigma height and anther height of the long flower and short flower of the Persicaria criopolitana shows that the stamen and stigma of the long and short stigma have interactive male and female ectopic,confirming that the Persicaria criopolitana is a typical diploid plant,which can pass Style high or anther high to distinguish different patterns.According to the relevant measurements and scanning electron microscopy,the diameter of the long-column corolla is slightly smaller than that of the short-column flower;the shape of the stigma of the two-type flower is the same,but the diameter of the long-column stigma is 265.34±84.71 um,and the diameter of the short-column stigma is 165.36±37.39 um.The long column type stigma is obviously larger than the short column type,and has a large stigma protrusion and a small protrusion density;the short column type pollen grain size is 62.84±4.33um×60.00±5.51 um,and the long column type pollen size is about 62.34±10.83um×58.94±9.40 um,the short column type is slightly larger than the long column type.In the same pattern,the length of the female and stamen were significantly different,and showed a significant negative correlation(r=-0.987,P=0.000).There was no significant difference between the male and female total lengths,indicating that there may be a trade-off relationship between the male and female total lengths.2.Flowering phenology and pollination characteristicsThe flower and fruit period of Persicaria criopolitana is from mid-October to December of each year.The flowering period is generally in November,and the final flowering period is in early December.The L-type and S-type florscence in the population maintained a high degree of flowering synchronization,which was 42 and 45 days respectively,,the difference is not significant.The average flowering duration of each plant was 22 d,the L-type inflorescence lasted for 12-22 days,the average value was 21 days,the S-type inflorescence lasted for 13-26 days,and the mean value was 24 days.The flowering stage of S-type inflorescence was significantly longer than that of L-type population.The duration of a single flower is about 1?2 days,the flowering period of the population is 42 and 45 days respectively,and most flowers are open between 8:00-12:00.There were some differences in the pollen vigor of different styles of Persicaria criopolitana.After flowering,the pollen vigor of both flower types increased gradually,and finally decreased.At the beginning of flowering,the pollen had vitality.After 4 hours of flowering,its pollen vigor reached the highest 74.93%,after 10 hours of flowering,most of the pollen lost its vitality..S-type pollen vigor is higher than L-type,but its single-flower pollen is lower than L-tyle.The stigma receptivity continued longer time.The L-type and S-type are still accessible at 72 h and 96 h respectively.Overall,the S-type stigma can last longer than the L-type.The main flower-seeking insects were(bees,cabbage butterflies,and scorpion flies),and the flowers of the two flower types had no significant difference in insect attraction.3.Breeding system and breeding strategyThe reproductive system was studied by comparing the pollen/ovule ratio(P/O),out-crossing index(OCI),emasulation and pollen tube germination of Persicaria criopolitana.The P/O rations of L-type and S-type flowers were respectively 248±33.6 and 249.37±38.74,ranging from 31.9 to 396.0,indicating that they were facultative heterosexual plants and required pollinators.The emasulation showed that the Persicaria criopolitana was self-incompatible and self-incompatibility,and the self-crossing was not compatible.The self-crossing between the types had affinity,but the seed setting rate was extremely low.Under natural conditions,Persicaria criopolitana blooms in a large area,but it is rarely sturdy,but it is mainly developed by the developed underground stems.It is a typical plant with more flowers and less fruits.There was no significant difference in the morphology of the seeds of the two types of plants.