金华市郊10种杂草的热值和灰分含量及其适应意义

在金华市郊,选择了婆婆纳(Veronica didyma)、水蓼(Polygonum hydropiper)、车前(Plantago asiatica)、北美车前(Plantago virginica)、毛茛(Ranunculus japonicus)、商陆(Phytolacca acinosa)、鹅观草(Roegneriakamoji)、早熟禾(Poa annua)、北美独行菜(Lepidium virginicum)、窃衣(Torilis japonica)等10种常见杂草,测定了生殖生长时期这些杂草不同器官的热值和灰分含量.研究结果表明,10种杂草花穗、叶、茎和根的干重热值的平均值分别为15.942、14.293、13.344和13.463 kJ/g,去灰分热值平均为16.983、16.219、14.480和15.233 kJ/g,整体上表现出花穗>叶>根>茎的趋势;10种杂苹的花穗、叶、茎和根中的平均灰分含量为6.127%、11.899%、8.071%、11.383%,叶片和根中的灰分含量较高,花穗与茎中的较低.对于北美车前来讲,随着生长时间的推移,北美车前的营养器官热值下降,随着种群密度的上升,北美车前的繁殖器官干重热值上升.采取低热值策略可能是杂草适应严酷环境的选择方式,具有进化上的积极意义.

On caloric values and ash contents of ten weed species in Jinhua suburb and its adaptive significances

In the suburb of Jinhua,the caloric values and ash contents of ten weed species were measured during their reproductive periods.These ten species include Veronica didyma,Polygonum hydropiper,Plantago asiatica,Plantago virginica,Ranunculus japonicus,Phytolacca acinosa,Roegneria kamoji,Poa annua,Lepidium virginicum and Torilis japonica.The main results are as follows: The average gross caloric values of the spikes,leaves,stems and roots of the ten weed species were(15.942),(14.293),(13.344) and(13.463 kJ/g) respectively,their average ash-free caloric values are(16.983),(16.219),(14.480) and(15.233 kJ/g),showing the order as spike > leaf > root > stem according their caloric values.The average ash contents of the spikes,leaves,stems and roots of these ten weeds were(6.127 %),(11.899 %),(8.071 %) and(11.383 %) respectively,revealing that the leaves and roots had higher ash contents than their spikes and stems.The vegetative caloric values of Plantago virginica declined with the growth period,and their productive caloric values became higher with the increase of their population density.Analyses indicated that the weed species having lower caloric values might be a good choice to their adaptation to the undesirable environments,with obvious positive evolutionary significances.