榄李开花生物学和繁育系统OACSTPCD

In order to reveal the endangered mechanism and carry out related conservation actions of Lumnitzera racemosa,we observed the flowering dynamics of the introduced L.racemosa in Dangan Island Provincial Nature Reserve,Zhuhai,Guangdong,and investigated the breeding system of L.racemosa by using the out-crossing index(OCI),pollen-ovule ratio(P/O),pollen viability and stigma receptivity,and artificial pollination.The results showed that:(1)The flowering period of L.racemosa population started May 16,the full blooming period was from May 25 to July 1,and the last flowering period was from July 5 to August 31,and the flowering period of L.racemosa population was up to 106 days.The flowering duration of inflorescence was 5-18 days,and average duration was(10.80±3.58)days;The single flowering period of L.racemose lasted 7-13 days,with an average of(9.1±1.3)days.(2)Pollen viability was highest on the day of flowering,reaching 58.73%,and decreased on the second day and no longer viable was on the third day;Stigma receptivity was weakest at the first day of opening,then gradually strengthened,and was strongest at 100%at the third day,and maturity time of male and female was inconsistent.(3)OCI was 4,the breeding system of L.racemosa was mainly outcrossing with partial self-compatible,which required pollinator;P/O was 5 740.50±1 318.20,the breeding system was obligate xenogamy;pollination test showed that the breeding system was a mixed mating system with both self and xenogamy.Based on the above,the breeding system of L.racemosa was mainly outcrossing with partial self-compatibility and requiredr pollinators.