The Variation Of Reproductive Characteristics Within Individuals Of Sambucus Chinensis Lindl.(Caprifoliaceae)

Sambucus chinensis Lindl.belongs to Caprifoliaceae,Sambucus Linn.which has cyathiform bisexual flowers and strong adaptability to environment,widespread.This study selected S.chinensis Lindl.as the research object and was conducted in Wenjiang,Sichuan and Ya'an.We surveyed basic floral characteristics and the variation of reproductive characteristics within individuals.In the study of the three populations between 2016 and 2017,We observed pollinator behaviors and the differences of flower visiting frequency of different time of the same day,the variation of some floral traits(such as lifetime,diameter,dry weight of single flower,dry weight of extra-floral nectary,number of flowers and extra-floral nectaries)and fruit period traits(such as fruit set,fruit conversion,fruit rates,seeds number and seeds dry weight per fruit)of different positions within individuals of S.chinensis Lindl..The results show as follows:(1)The pollination behaviors of pollinators of S.chinensis: Three main pollinators of S.chinensis were bees,flies and butterflies.Change in flower visiting frequency of insects during a day was evident(Population 1: P = 0.016,Population 2: P < 0.001).The differences of tiny plant environment and the different pollination behavior may lead to the difference of flower visiting frequency of insects during a day.(2)According to the position of flower heads,the inflorescence can be divided into three levels: primary,secondary,and third level(Figure 2),which represent different positions within individuals of S.chinensis Lindl.,be written as position 1,position 2,position 3.The flower lifetime,flower diameter,dry weight of flower and extra-floral nectary,number of flowers and extra-floral nectaries the rate of flowers and extra-floral nectaries of different positions within individuals all have significant differences of S.chinensis Lindl.(all P < 0.05).Among the results,the rate of flowers and extra-floral nectaries and the flower lifetime both increase first then decrease from position 1 to position 3 within individuals(position 2 highest,position 1 lowest).The flower diameter,dry weight of single flower and extra-floral nectary all show significant decrease progressively from position 1 to position 3 within individuals.However,the number of flowers and extra-floral nectaries show significant increase progressively from position 1to position 3.(3)The number of visiting ants and extra-floral nectaries of different positions within individuals didn't show significant differences of S.chinensis Lindl.(all P > 0.05).The trend of the number of visiting ants and extra-floral nectaries increase first then decrease from position 1 to position 3 within individuals is not so obvious,which means that the degree and the trend of variation of visiting ants and extra-floral nectaries number of different positions within individuals are similar.The number of visiting ants and extra-floral nectaries of the three positions of Population One are all higher than Population Two of Ya'an,which means that the number of visiting ants and extra-floral nectaries shows similar differences between the two populations.The results of correlation analysis show that the number of visiting ants and extra-floral nectaries have significant positive correlation at individual level of S.chinensis Lindl.(r=0.910,r=0.901).(4)The fruit set,fruit conversion,fruit rate and seeds dry weight per fruit of different positions show significant differences within individual of S.chinensis Lindl.(all P < 0.05).However,the seeds number per fruit didn't show significant difference among the three positions within individuals(all P > 0.05)and always be the difinite value ‘3'.The fruit set,fruit conversion and fruit rate all increase first then decrease from position 1to position 3 within individuals(position 2 highest,position 1 lowest).However,the seeds dry weight per fruit show significant decrease progressively from position 1 to position 3within individuals of S.chinensis Lindl..In conclusion,the reproductive characteristics of different positions within individuals of S.chinensis Lindl.show extensive variability.The variation degree and the variation trend are different among different traits.Even the same trait may show different variation pattern among different populations or different year.Also,few reproductive characteristics didn't change among positions within individuals.The extensive variations within individual may be a kind of effective reproductive strategy of S.chinensis Lindl..