Villar Rafael, Veneklaas Erik J, Jordano Pedro, Lambers Hans
Department of Plant Ecology and Evolutionary Biology, Utrecht University, P.O. Box 800.84, 3508 TB Utrecht, The Netherlands.
To whom correspondence should be addressed.
New Phytol. 1998 Nov;140(3):425-437. doi: 10.1111/j.1469-8137.1998.00286.x.
This paper analyses relationships between relative growth rate (rgr), seed mass, biomass allocation, photosynthetic rate and other plant traits as well as habitat factors (rainfall and altitude) in 20 wild species of Aegilops L. and one closely related species of Amblyopyrum (Jaub. & Spach) Eig., which differ in ploidy level (diploid, tetraploid and hexaploid). The plants were grown hydroponically for 20 d in a growth chamber. The relationships between parameters were calculated either using the phylogenetic information (phylogenetically independent contrasts, PIC) or without using the phylogenetic information (trait values of taxa, TIP). The results using the two approaches were very similar, but there were a few exceptions in which the results were different (e.g. rgr vs. seed mass). Specific leaf area (sla) was positively correlated with leaf area ratio (lar) and negatively correlated with net assimilation rate (nar), which together resulted in the absence of a correlation between sla and rgr. Leaf photosynthetic rates (expressed on a mass or area basis) showed no correlation with rgr. rgr was positively correlated with the stem mass ratio and negatively with root mass ratio. Species with a lower d. wt percentage have a higher rgr. Aegilops species from locations with higher annual rainfall invested less biomass in roots and more in shoots (leaves and stems) and had a higher rgr. Diploid species had a lower seed mass and initial mass than the hybrids (tetraploid and hexaploid species), but there was no correlation of rgr with ploidy level. Polyploid species, which have higher seed mass, occur at a higher altitude than diploid species. Our results show that variation in rgr in Aegilops and Amblyopyrum spp. is associated mainly with variation in biomass allocation (proportion of biomass in stems and roots) and d. wt percentage, and not with variation in sla, leaf photosynthetic rates or seed mass.
本文分析了20种野生山羊草属（Aegilops L.）植物以及一种与之亲缘关系密切的钝稃草属（Amblyopyrum (Jaub. & Spach) Eig.）植物（它们的倍性水平不同，包括二倍体、四倍体和六倍体）的相对生长速率（rgr）、种子质量、生物量分配、光合速率及其他植物性状与栖息地因素（降雨量和海拔）之间的关系。这些植物在生长室内水培20天。参数之间的关系通过使用系统发育信息（系统发育独立对比，PIC）或不使用系统发育信息（分类群的性状值，TIP）来计算。两种方法得到的结果非常相似，但也有一些例外情况，结果有所不同（例如rgr与种子质量）。比叶面积（sla）与叶面积比（lar）呈正相关，与净同化率（nar）呈负相关，这共同导致sla与rgr之间不存在相关性。叶片光合速率（以质量或面积为基础表示）与rgr无相关性。rgr与茎质量比呈正相关，与根质量比呈负相关。干重百分比较低的物种具有较高的rgr。来自年降雨量较高地区的山羊草物种在根部投入的生物量较少，在地上部分（叶和茎）投入的较多，且rgr较高。二倍体物种的种子质量和初始质量低于杂种（四倍体和六倍体物种），但rgr与倍性水平无相关性。种子质量较高的多倍体物种比二倍体物种出现在更高的海拔处。我们的结果表明，山羊草属和钝稃草属物种rgr的变化主要与生物量分配（茎和根中生物量的比例）和干重百分比的变化有关，而与sla、叶片光合速率或种子质量的变化无关。
