Pollard A Joseph, Baker Alan J M
Department of Biology, Furman University, Greenville, SC 29613, USA.
Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
New Phytol. 1996 Jan;132(1):113-118. doi: 10.1111/j.1469-8137.1996.tb04515.x.
We examined variation within and between populations of Thlaspi caerulescens J. & C. Presl (Brassicaceae). a plant species known to hyperaccumulate zinc to foliar concentrations exceeding 3 % (d.wt basis). Seeds were collected as sib families from two populations in Derbyshire, UK along with leaf samples from the parent plants. Offspring were grown hydroponically from seed, in culture solution containing 10 mg 1 Zn. Significant differences in zinc concentration and plant size were Found between populations and among sib families within populations. Heritability analysis based on resemblance among sibs revealed significant heritable variation within one population, but not the other. The characters of zinc accumulation and plant size were not correlated. Parent-offspring recession did not prove useful for estimation of heritability, because of heterogeneity in metal availability to parents growing in the field. The results are relevant to attempts to exploit metal hyperaccumulation as a technology for remediation of contaminated soil, and to our understanding of the evolutionary origins of the phenomenon of hyperaccumulation.
我们研究了天蓝遏蓝菜（十字花科）种群内部和种群之间的变异。天蓝遏蓝菜是一种已知能将锌超积累到叶片浓度超过3%（干重基础）的植物物种。种子作为同胞家系从英国德比郡的两个种群收集，同时收集了亲本植株的叶片样本。种子后代在含有10 mg/L锌的培养液中进行水培生长。在种群之间以及种群内的同胞家系之间发现了锌浓度和植株大小的显著差异。基于同胞相似性的遗传力分析表明，一个种群内存在显著的可遗传变异，而另一个种群则没有。锌积累特性和植株大小不相关。由于田间生长的亲本获取金属的异质性，亲子回归分析对于遗传力的估计并无帮助。这些结果与利用金属超积累作为污染土壤修复技术的尝试相关，也有助于我们理解超积累现象的进化起源。
