Different breeding systems of three varieties of Bidens pilosa in Taiwan

作者：Huang Y L; Kao W Y^*

来源：Weed Research, 2014, 54(2): 162-168.

DOI：10.1111/wre.12060

• pollen/ovule ratio
• pollen-pistil interaction
• invasive plant
• hairy beggar-ticks
• mating system
• self-incompatibility

Three varieties of the introduced Bidens pilosa (Hairy beggar-ticks; Asteraceae) co-exist in Taiwan. Bidens pilosa var.minor and var.pilosa are naturalised, while only var.radiata is invasive. Differences in seed set in bagged versus open-pollinated capitula, pollen-pistil interactions and the pollen/ovule (P/O) ratio were investigated among these three varieties. In contrast with the resulting 45-55% seed set in each bagged capitulum of var.minor and var.pilosa, almost no mature seeds (1-2 seeds) were found in bagged capitula of var.radiata, showing that var.radiata has a low capability of autonomous seed production. In bagged capitula, only 1.5% of pistils of var.radiata, but 76% and 52% of those of var.minor and pilosa, respectively, had pollen tubes penetrating into their styles, suggesting that var.radiata has strong self-incompatibility mechanisms preventing autonomous autogamy. The P/O ratio, with mean values of 8189, 2053 and 1613 for var.radiata, var.minor and var.pilosa, respectively, were counted. These results support the hypothesis that the three varieties bear different breeding systems; the invasive var.radiata is highly self-incompatible, whereas the other two naturalised varieties are self-compatible.

• 出版日期2014-4