【摘要】：柑橘作為世界第一大果樹,是典型的亞熱帶植物。在柑橘類植物中只有枳屬(Poncirus trifoliata)具有落葉性。落葉性在植物的生長發(fā)育過程中起著重要的作用,如促進(jìn)休眠,減少蒸騰作用,提高抗寒性等。近年來,有文章以常綠柑橘為材料研究干旱或乙烯處理等逆境條件下的離層形成與葉片脫落現(xiàn)象,而以枳屬為試材研究落葉機理的文章少之又少。因此,弄清控制柑橘落葉的原因及其內(nèi)在基因調(diào)控機理具有重要的意義。本試驗以早實枳和克里曼丁橘為主要研究材料,探究枳不同于常綠柑橘的一種與季節(jié)變換相適應(yīng)的主動性落葉抗寒機制。主要研究結(jié)果如下:1.利用石蠟切片技術(shù)對早實枳和克里曼丁橘的一年生莖和葉進(jìn)行橫切,觀察莖和葉的維管束(導(dǎo)管)結(jié)構(gòu)差異,發(fā)現(xiàn)早實枳的導(dǎo)管管徑、導(dǎo)管數(shù)量以及寬導(dǎo)管比例均比克里曼丁橘小,說明早實枳的導(dǎo)管吸水能力比克里曼丁橘弱,但其窄導(dǎo)管輸導(dǎo)水分更安全,更有利于適應(yīng)低溫逆境環(huán)境抵御冬季嚴(yán)寒;2.對早實枳和克里曼丁橘的一年生枝條在落葉前后進(jìn)行樹體生理指標(biāo)的測定,即相對電導(dǎo)率變化、丙二醛含量、脯氨酸含量、可溶性糖含量以及可溶性蛋白含量的測定,以觀察兩品種在落葉前后的樹體生理指標(biāo)變化和抗寒力變化。結(jié)果表明在自然溫度變化下,早實枳比克里曼丁橘更能適應(yīng)低溫環(huán)境;3.本實驗室前期通過QTL定位、基因功能注釋以及對枳幼苗低溫處理進(jìn)行qRT-PCR共篩選出了30個落葉候選基因,從中挑選出5個基因構(gòu)建超表達(dá)載體,并轉(zhuǎn)到模式植物番茄中異位表達(dá),以進(jìn)行該基因的功能驗證。結(jié)果表明超表達(dá)轉(zhuǎn)基因株系35S::ABS3和35S::ABS7比野生型對照植株更能適應(yīng)低溫環(huán)境。說明ABS3和ABS7基因可以響應(yīng)低溫誘導(dǎo)。4.本實驗通過了解枳落葉性狀的遺傳規(guī)律和落葉關(guān)聯(lián)基因的功能,以進(jìn)一步認(rèn)識落葉植物不同于常綠植物的主動適應(yīng)氣候變換,獲得在寒冷地區(qū)生存能力的特性,為進(jìn)一步研究柑橘抗寒分子育種提供重要的理論基礎(chǔ)。
[Abstract]:Citrus, as the largest fruit tree in the world, is a typical subtropical plant. Among citrus plants, only (Poncirus trifoliata) has deciduous properties. Deciduous property plays an important role in plant growth and development, such as promoting dormancy, reducing transpiration and improving cold resistance. In recent years, evergreen citrus has been used to study the formation of layer separation and leaf shedding under drought or ethylene treatment, but there are few articles on the deciduous mechanism of trifoliate (Trifoliate orange). Therefore, it is of great significance to understand the cause of controlling citrus leaves and its intrinsic gene regulation mechanism. In this study, we studied the active deciduous cold resistance mechanism of trifoliate orange, which is different from evergreen citrus, and adapted to seasonal change. The main results are as follows: 1. The annual stems and leaves of precocious trifoliate orange and Cleimanthus trifoliate were crosscut by paraffin section technique. The differences of vascular bundle (vessel) between stem and leaf were observed and the diameter of ductal tube of precocious trifoliate orange was found. The number of ducts and the ratio of wide ducts were smaller than those of Creman's, which indicated that the ducts of precocious trifoliate orange were weaker in water absorption than those of Cleimanthus, but its narrow conduits were safer to transport water, which was more advantageous to adapt to the low temperature environment and resist the cold in winter. The physiological indexes of the annual branches of precocious trifoliate and Crymannia were measured before and after the fallen leaves, namely the relative electrical conductivity, the content of malondialdehyde, the content of proline, the content of soluble sugar and the content of soluble protein. The changes of physiological indexes and cold resistance of the two varieties before and after falling leaves were observed. The results showed that the precocious trifoliate orange could adapt to low temperature environment better than Creman's under natural temperature. A total of 30 deciduous candidate genes were screened by QTL mapping, gene function annotation and qRT-PCR treatment of trifoliate seedlings in the early stage of the experiment, and 5 genes were selected to construct superexpression vector and transferred to heterotopic expression in model plant tomato. To verify the function of the gene. The results showed that the overexpression transgenic lines 35S::ABS3 and 35S::ABS7 could adapt to low temperature environment better than wild-type control plants. These results suggest that ABS3 and ABS7 genes can respond to hypothermia induction. 4. In order to further understand the active adaptation of deciduous plants from evergreen plants to climate change and to obtain the characteristics of survival ability in cold regions, the genetic rules of defoliation traits and the functions of deciduous associated genes in trifoliate orange (Trifoliate trifoliate) were studied in this experiment. It provides an important theoretical basis for further study on cold resistant molecular breeding of citrus.
【學(xué)位授予單位】：華中農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S666

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 田曉涵;龐學(xué)兵;祝建波;朱新霞;;過表達(dá)天山雪蓮SikCDPK1基因提高轉(zhuǎn)基因煙草耐低溫能力的機制初探[J];中國煙草學(xué)報;2016年06期

2 何利剛;蔣迎春;吳黎明;仝鑄;王志靜;許淼;孫中海;;幾種柑橘資源的抗寒性測定及初步評價[J];農(nóng)業(yè)科技通訊;2015年05期

3 何壽仁;齊偉;;江西南豐蜜橘3次典型異常氣象災(zāi)害分析與思考[J];中國園藝文摘;2015年03期

4 白茹;高登濤;劉懷鋒;馮建榮;;引入石河子地區(qū)的葡萄砧木抗寒性研究[J];新疆農(nóng)業(yè)科學(xué);2015年02期

5 馬文濤;樊衛(wèi)國;;貴州野生柑橘的抗寒性測定和綜合評價[J];西北植物學(xué)報;2014年10期

6 王菲;尹燕雷;馮立娟;楊雪梅;王長君;;果樹抗寒性研究進(jìn)展[J];山東農(nóng)業(yè)科學(xué);2014年09期

7 蘭嵐;姚延h，

本文編號：2237492