發(fā)布時(shí)間：2018-04-17 19:43

  本文選題：霸王 + 埋放種子　； 參考：《新疆師范大學(xué)》2017年碩士論文

【摘要】：霸王(Zygophyllum xanthoxylon)為蒺藜科超旱生灌木,是達(dá)坂城荒漠植被的優(yōu)勢(shì)種,是植被恢復(fù)的潛在候選植物種。本研究通室內(nèi)實(shí)驗(yàn)和野外觀測(cè),對(duì)霸王在達(dá)坂城原生境埋放及植冠宿存的種子進(jìn)行了研究,并調(diào)查其霸王在自然條件下出苗的時(shí)空格局,對(duì)其種子萌發(fā)階段對(duì)達(dá)坂城極端干旱和長(zhǎng)期大風(fēng)環(huán)境的適應(yīng)對(duì)策進(jìn)行了探討,主要結(jié)論如下:(1)霸王種子成熟時(shí)有部分種子(39%)存在休眠。在達(dá)坂城地區(qū),季節(jié)性水熱條件的變化能夠影響種子的萌發(fā)和休眠。鮮種子的休眠在原生境埋放6周后逐漸解除,秋季(2015年9月)萌發(fā)率升高;埋放18周后經(jīng)過(guò)冬季的低溫層積后休眠基本解除,冬季(2015年12月)取回的種子在5/15℃下萌發(fā)率提高到87%以上;直到埋放42周后(2017年6月),有少部分種子(約21-49%)在夏季進(jìn)入次生休眠,種子萌發(fā)的溫度范圍改變,萌發(fā)率在高溫下(25/15℃、30/15℃)降低;直到之后的秋季,埋放54周(2017年9月)的種子休眠解除,萌發(fā)率再次升高;埋放70周(2017年12月)的種子經(jīng)過(guò)第二年冬季低溫層積后萌發(fā)率均在97%以上,仍有93%以上的種子有活力。在較高溫度下地表種子比土中具有更高的萌發(fā)率。在達(dá)坂城荒漠,土壤中埋放的霸王種子具有季節(jié)性的條件休眠/非休眠的循環(huán)。(2)在達(dá)坂城地區(qū),植冠宿存4、6個(gè)月后的種子萌發(fā)率仍在93%以上。霸王植冠宿存6個(gè)月的種子萌發(fā)率明顯高于地表種子。植冠種子的活力高于地表種子,植冠宿存有利于種子活力的保持。(3)在達(dá)坂城地區(qū),霸王在整個(gè)生長(zhǎng)季內(nèi)均能出苗,5月、6月、7月、8月、9月、10月出苗數(shù)分別為0.02株/m2、0.4株/m2、2.9株/m2、0.7株/m2、5.8株/m2、2.4株/m2,出苗的主要季節(jié)是秋季。出苗的微生境主要在麻黃叢、低洼裸地、單株霸王背風(fēng)面。
[Abstract]:Zygophyllum xanthoxylon is a super xerophytic shrub of Tribulus terrestris family. It is the dominant species of desert vegetation in Dabancheng and a potential candidate for vegetation restoration.Through laboratory experiments and field observation, the seeds planted and planted in the original habitat of Dabancheng were studied, and the temporal and spatial patterns of Seedling emergence under natural conditions were investigated.In this paper, the adaptation strategies of Dabancheng extreme drought and long term strong wind environment during seed germination were discussed. The main conclusions are as follows: 1) some seeds have dormancy when they mature.In Dabancheng, seasonal changes in water and heat conditions can affect seed germination and dormancy.The dormancy of fresh seeds was gradually released after 6 weeks of planting in the original habitat, and the germination rate increased in autumn (September 2015), and after 18 weeks of burial, the dormancy was basically relieved after the cold stratification in winter.In winter (December 2015), the seed germination rate increased to more than 87% at 5 / 15 鈩，

本文編號(hào)：1765007