珍稀濒危植物陕西羽叶报春的开花及传粉生物学研究

Flowering and Pollination Biology of Rare and Endangered Plant Primula filchnerae Knuth

陕西羽叶报春为中国珍稀濒危植物,研究其开花物候、传粉者及访花行为、花粉活力、柱头可授性、繁育系统,以明确陕西羽叶报春的传粉特性及制濒机制。以勉县陕西羽叶报春野生居群为研究对象,通过野外观察和人工授粉实验首次对陕西羽叶报春的传粉生物学进行研究。结果表明:(1)陕西羽叶报春种群花期为2-4月中旬,单花花期一般为14~17 d;单花开花进程中花部形态有6个明显发育变化:全部被萼片包裹、花苞伸出并为深粉色、花朵打开为淡粉色、花冠为白色、花朵枯萎、花冠脱落花萼宿存。(2)陕西羽叶报春为异花授粉植物,蜜蜂属为其主要传粉者。(3)柱头在花粉未开裂前就具有可授性,可授性逐渐增强;花药在花瓣打开后的第3天才开始开裂、散粉,在第4天活力最高,为98.18%,此后逐渐减弱。(4)繁育系统检测显示,长、短柱型花的花粉/胚珠比分别为902.26和831.48,杂交指数为4;套袋实验显示,陕西羽叶报春异型交配可育,同型交配不可育。由此表明,陕西羽叶报春的繁育系统为异交型,自交不亲和,需要传粉者。综上所述,陕西羽叶报春传粉者种类少、自交不亲和、胚珠败育现象可能是导致陕西羽叶报春濒危的重要原因。

Primula filchnerae Knuth is a rare and endangered plant in China.This paper studied the flowering phenology,pollinator and flower visiting behavior,pollen vitality,stigma receptivity,breeding system,and clarify pollination characteristics and endangered mechanism of P.filchnerae.Taking the wild population of P.filchnerae in Mianxian as the research object,the pollination biology of P.filchnerae was studied for the first time through field observation and artificial pollination experiments.The results showed that:(1)The flowering period of the P.filchnerae population was from February to mid-April,the single-flowered flowering period is generally for 14 to 17 days.There were 6 obvious developmental changes in the flower morphology during the single flower flowering process,which were all wrapped by sepals,buds extended and showed dark pink,flowers opened and showed pale pink,corolla was white,flowers withered,corolla fell off and calyx persistent.(2)P.filchnerae was an outcrossing plant pollinated by Apis.(3)The stigma was receptive before the anthers dehiscence,the receptivity gradually increased,the anthers began to dehiscence and loose pollen on the third day after the petals opened,the vitality was the highest on the fourth day at 98.18%,then gradually weakened.(4)A study of the breeding system indicated that the pollen-ovule ratio of the long-styled and the short-styled were 902.26 and 831.48 respectively,the hybridization index(OCI)was 4,bagging experiment show that the heterozygous mating is fertile and homozygous mating is not fertile.This shows that the breeding system of P.filchnerae is outcrossing and self-incompatible,it needs pollinators.In conclusion,few pollinators,self-incompatible,ovule abortion may be the important reasons for the endangerment of P.filchnerae.