Pollen and Resource Limitation in Veratrum nigrum L. (Liliaceae), an Andromonoecious Herb

Abstract

Pollen limitation and resource limitation were invoked to account for the pattern that flowering plants produce more flowers and ovules than fruits and seeds. This study aimed to determine their relative importance in Veratrum nigrum, a self-compatible, perennial, andromonoecious herb. In order to determine whether female production was limited by pollen grains on stigmas or by available resources, we performed supplemental hand pollination in three populations, male-flower-bud removal in three other populations, and emasculation of hermaphroditic flowers in still another population , resulting in a total of seven populations experimentally manipulated. Across the three populations, supplemental hand pollination did not significantly increase fruit set, seed number per fruit, and total seed production per individual, nor did emasculation of hermaphroditic flowers. Taken together, our results suggest that pollen grains deposited on stigmas were abundant enough to fertilize all the ovules. Male-flower-bud removal significantly increased the mean size of hermaphroditic flowers in all three populations. Female reproductive success was increased in one population, but not in the other two populations possibly due to heavy flower/seed predation. We concluded that the female reproductive success of V. nigrum was not limited by pollen grains but by available resources, which is consistent with Bateman's principle. Furthermore, the female reproduction increase of male-flower-bud removal individuals might suggest a trade-off between male and female sexual functions.Flowering plants often produce more flowers and ovules than fruits and seeds. Two proximate ecological mechanisms account for this pattern: insufficient pollen delivery to stigmas and limited resources for maturation of fruits and seeds

An Examination of the Function of Male Flowers in an Andromonoecious Shrub Capparis spinosa

“…Fruiting success probably was limited by resources and not by the number of fertile ovaries. The hand pollination experiment showed that seed production also was not limited by pollen, although this may vary among sites and among years depending mainly on insect pollinator abundance (Liao et al 2006).…”

Increased Maleness at Flowering Stage and Femaleness at Fruiting Stage with Size in an Andromonoecious Perennial,Veratrum nigrum

“…If so, seed set in small plants should be limited by compatible pollen gains deposited on stigma, rather than by resources available for seed maturation. However, this hypothesis is unlikely since the female reproductive success is not pollen‐limited, but resource‐limited in V. nigrum (Liao et al 2006).…”

Male flowers in Tulipa pumila Moench (Liliaceae) potentially originate from gender diphasy

“…In the last two decades, the occurrence of femalesterile systems has been highlighted in an increasing number of studies dealing with taxa in the order Liliales (e.g., Beisenova et al, 2015;Dafni & Shmida, 2002;Liao, Song, & Zhang, 2006;Liao & Zhang, 2008;Nishikawa, 1998;Schnittler et al, 2017;Wang, Zhai, & Zhang, 2018). In particular, within Liliaceae, several cases have been previously reported in Fritillaria (Mancuso & Peruzzi, 2010;Matsuura, 1934;Peruzzi, 2012;Peruzzi, Mancuso, & Gargano, 2012;Shimizu et al, 1998), Gagea (including Lloydia) (Jones & Gliddon, 1999;Niu, Gong, Peng, Sun, & Li, 2017) and Lilium (Peruzzi, 2012;Zhang et al, 2014).…”