Lee T D, Bazzaz F A
Department of Botany and Plant Pathology, University of New Hampshire, 03824, Durham, NH, USA.
Department of Organismic and Evolutionary Biology, Harvard University, 02138, Cambridge, MA, USA.
Oecologia. 1986 Sep;68(3):459-465. doi: 10.1007/BF01036755.
We examined the extent of ovule abortion and the within-fruit pattern of abortion inCassia fasciculata, an annual legume, and tested the hypothesis that abortion can result from competition for limited maternal resources among developing fruits and seeds. In a natural population at Mayview, IL, 53.4% of ovules in mature fruits matured as seeds; 43.4% showed some development but aborted, and 3.1% showed no development over virgin ovules. In a greenhouse experiment in which treatments were applied after most fruits were initiated, nutrient addition and partial root removel had no effect on abortion, but drought reduced the proportion of ovules maturing to 75% of the control mean. A fruit thinning experiment was conducted in which the number of fruits initiated on certain plants was limited. Control plants had more ovule abortion than fruit-thinned plants, suggesting that abortion resulted from competition for limited maternal resources. A "position effect" was observed in both field and greenhouse populations; ovules toward the fruit base (pedicellar end) had higher frequencies of abortion than those at the distal end. Thus, ovule abortion, like fruit abortion in this species, is non-random. Indivisuals regulate fecundity at both the whole fruit and individual seed levels.
我们研究了一年生豆科植物束花决明（Cassia fasciculata）胚珠败育的程度以及果实内部的败育模式，并检验了以下假设：败育可能是由于发育中的果实和种子之间对有限母体资源的竞争所致。在伊利诺伊州梅维尤的一个自然种群中，成熟果实中53.4%的胚珠发育成种子；43.4%有一定发育但败育，3.1%与未受精胚珠相比未发育。在一个温室实验中，在大多数果实形成后进行处理，添加养分和部分去除根系对败育没有影响，但干旱使发育成种子的胚珠比例降至对照平均值的75%。进行了一项果实疏果实验，限制某些植株上形成的果实数量。对照植株比疏果植株有更多的胚珠败育，这表明败育是由于对有限母体资源的竞争所致。在田间和温室种群中均观察到“位置效应”；靠近果实基部（花梗端）的胚珠败育频率高于远端的胚珠。因此，胚珠败育，就像该物种的果实败育一样，是非随机的。个体在整个果实和单个种子水平上调节繁殖力。
