本文選題：西瓜 + 枯萎病��； 參考：《甘肅農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：西瓜枯萎病是一種嚴(yán)重危害西瓜生產(chǎn)的世界性土傳病害,隨著設(shè)施栽培面積的擴(kuò)大,重茬連作導(dǎo)致枯萎病大面積發(fā)生,選育和篩選抗病嫁接砧木是解決西瓜枯萎病有效的途徑之一。西瓜屬于喜溫作物,對低溫極為敏感,我國北方大部分地區(qū)的設(shè)施栽培方式均以春提早和秋延遲栽培為主,北方冬春季節(jié)溫度較低,低溫常會(huì)影響設(shè)施西瓜的生長發(fā)育,制約西瓜產(chǎn)量和品質(zhì)的提高。通過使用耐冷性較強(qiáng)的嫁接砧木材料,可顯著提高接穗品種的耐冷性,為了更好地適應(yīng)我國北方地區(qū)設(shè)施栽培的環(huán)境,要求篩選出既抗枯萎病,同時(shí)耐低溫的西瓜嫁接砧木材料,因此,開展西瓜砧木組合材料的枯萎病抗性鑒定、砧木幼苗耐冷性評價(jià)及耐冷性生理機(jī)制研究具有重要的現(xiàn)實(shí)意義。本研究以選配的39份西瓜砧木組合為試材,采用尖鐮孢菌(Fusarium oxysporum f.sp.niveum)孢子懸浮液人工接種法,篩選出3份優(yōu)良抗病砧木組合材料,在此基礎(chǔ)上,通過人工氣候箱控制溫度條件,研究了低溫10℃/5℃(晝/夜)(重度低溫)、15℃/10℃(晝/夜)(中度低溫)和25℃/18℃(晝/夜)(適宜溫度)處理對3份西瓜抗病砧木幼苗生長發(fā)育、葉片生理生化特性及根系養(yǎng)分吸收特性的影響,以探討西瓜抗病砧木幼苗對低溫環(huán)境的適應(yīng)性及耐冷性生理機(jī)制,闡明低溫條件下幼苗根系對N、P、K的吸收轉(zhuǎn)運(yùn)規(guī)律,為西瓜抗病砧木材料的抗逆性鑒定評價(jià)及設(shè)施西瓜栽培中養(yǎng)分科學(xué)管理提供理論依據(jù)。主要研究結(jié)果如下:1.鑒定出本試驗(yàn)所用尖孢鐮刀菌為1號生理小種(Race1)。39份西瓜材料中篩選出對Race1表現(xiàn)抗病的材料4份,占總供試材料的10.3%,中抗材料25份,占64.1%,輕抗材料10份,占25.6%,不存在免疫和完全感病材料。2.低溫脅迫使3個(gè)西瓜抗病砧木幼苗生長受到明顯抑制,冷害率和冷害指數(shù)顯著增加,低溫處理10d,3個(gè)西瓜砧木組合冷害率均達(dá)100%。低溫脅迫顯著抑制了‘BEH×Ag2-1’、‘BYH×FR328’和‘BEH×FR328’砧木組合的株高、莖粗、葉面積和葉片數(shù)的增加,顯著降低了砧木組合總干物質(zhì)的積累分配,結(jié)合外部形態(tài)觀察可知,‘BEH×Ag2-1’葉片邊緣輕度萎蔫,無脫水斑,心葉正常,受冷害最輕,‘BEH×FR328’葉片邊緣較重萎蔫,出現(xiàn)輕微脫水斑,心葉略失水,受冷害最重,3個(gè)西瓜抗病砧木組合耐冷性強(qiáng)弱順序?yàn)椤瓸EH×Ag2-1’‘BYH×FR328’‘BEH×FR328’。3.低溫脅迫顯著降低了3個(gè)西瓜抗病砧木葉片光合能力。低溫脅迫條件下,砧木葉片Chl(a+b)和Car,Chla/Chlb、Pn、Tr、Gs、WUE和Ls顯著降低,Ci顯著增大,非氣孔限制為光合下降主因,葉片F(xiàn)v/Fm、Fv/Fo、Y(Ⅱ)、ETR和qP顯著降低,‘BEH×FR328’葉片NPQ顯著降低,而‘BYH×FR328’和‘BEH×Ag2-1’葉片NPQ增加。隨低溫脅迫度增加,‘BEH×FR328’、‘BYH×FR328’和‘BEH×Ag2-1’葉片Chl(a+b)和Car,Chla/Chlb、Pn、Tr、Gs和Ls,Fv/Fm,Fv/Fo,Y(Ⅱ),ETR和q P降幅均依次減小。重度低溫(10℃/5℃)脅迫下,耐低溫型組合‘BEH×Ag2-1’葉片Chl(a+b)和Car,Chla/Chlb、Pn、Tr、Gs和Ls,Fv/Fm、Fv/Fo、Y(Ⅱ)、ETR和qP顯著高于低溫敏感型組合‘BEH×FR328’,而葉片Ci則相反�！瓸EH×Ag2-1’葉片吸收利用光能和傳遞電子效率較高,光合受抑制程度均小于其余2個(gè)砧木組合,‘BEH×FR328’光合機(jī)構(gòu)破壞,光合活性受損最重。4.低溫脅迫破壞了3個(gè)西瓜抗病砧木葉片膜完整性,啟動(dòng)了抗氧化酶系統(tǒng),增加了滲透調(diào)節(jié)物質(zhì)含量。低溫脅迫條件下,砧木葉片相對電導(dǎo)率、MDA含量、SOD、POD和CAT活性、可溶性糖、可溶性蛋白和脯氨酸含量顯著升高,隨低溫脅迫程度增加,‘BEH×FR328’、‘BYH×FR328’和‘BEH×Ag2-1’葉片相對電導(dǎo)率、MDA含量升高幅度依次減小,SOD、POD和CAT活性,可溶性糖、可溶性蛋白和脯氨酸含量升高幅度依次增大。重度低溫(10℃/5℃)脅迫下,耐低溫型組合‘BEH×Ag2-1’葉片相對電導(dǎo)率和MDA含量顯著低于中等耐性組合‘BYH×FR328’和低溫敏感型組合‘BEH×FR328’,葉片SOD、POD和CAT活性,可溶性糖、可溶性蛋白和脯氨酸含量顯著高于低溫敏感型組合�？寡趸富钚院蜐B透調(diào)節(jié)物質(zhì)含量增加增強(qiáng)了植株耐冷性,是西瓜抗病砧木抵抗低溫逆境的重要生理機(jī)制。5.低溫脅迫使3個(gè)西瓜抗病砧木幼苗根系生長受到明顯抑制。主根長、根體積、根系活力、根系總吸收面積和根系活躍吸收面積均顯著降低,耐低溫型組合‘BEH×Ag2-1’的上述根系指標(biāo)值均大于中等耐性和低溫敏感型組合。低溫脅迫顯著降低了3個(gè)砧木幼苗莖葉N、P、K含量和根系N、P含量,表明低溫降低了植株根系活力,抑制了根系對N、P和K元素的吸收。重度低溫(10℃/5℃)脅迫下,耐低溫型組合‘BEH×Ag2-1’幼苗根莖葉N、P、K含量顯著高于低溫敏感型組合‘BEH×FR328’。適溫對照(25℃/18℃)幼苗莖葉N、P、K含量高于根系,低溫脅迫下莖葉N、P、K含量低于根系,但含量無顯著性變化。
[Abstract]:Watermelon wilt is a worldwide soil borne diseases serious harm to watermelon production, with the expansion of cultivation area, cropping even lead to wilt disease occurrence, breeding and screening of resistant rootstocks is one of the effective ways to solve the Fusarium Wilt of watermelon watermelon. Belongs to thermophilic crops, the low temperature is very sensitive, greenhouse cultivation in most parts of North China in early spring and Qiu Yanchi cultivation in the northern winter season, low temperature, low temperature would affect the growth and development of watermelon, restrict the yield and quality of watermelon increased. Through the use of cold tolerance strong grafting materials, can significantly improve the cold tolerance of scion varieties, in order to better to adapt to the cultivation in northern China, which require screening of resistance to Fusarium Wilt of watermelon, grafting material, and low temperature resistance therefore carry out watermelon rootstock composite wilt Disease resistance identification, rootstock seedlings cold tolerance evaluation and research of cold resistance physiological mechanism has important practical significance. In this study, 39 watermelon rootstocks selected as test materials, by Fusarium oxysporum (Fusarium oxysporum f.sp.Niveum) spore suspension inoculation method, selected 3 excellent rootstocks resistant materials on this basis, the temperature control of artificial climate box, on the temperature of 10 DEG /5 DEG (day / night) (severe hypothermia), 15 /10 OC (day / night) (moderate hypothermia) and 25 DEG /18 DEG (day / night) (temperature) treatment on the development of 3 watermelon resistant rootstocks the growth of seedlings, affect the absorption characteristics of physiological and biochemical characteristics of root and leaf nutrient content, to explore the watermelon rootstock seedlings resistance to low temperature adaptability and cold resistance physiological mechanism, clarify the seedling roots under low temperature conditions on N, P, K absorption and transport law, watermelon resistant rootstocks resistant material Inverse nutrient management evaluation and identification of watermelon cultivation in facilities and provide a theoretical basis. The main results are as follows: 1. identified in this experiment with Fusarium oxysporum as race 1 (Race1).39 watermelon accessions were screened for Race1 resistant material 4, accounted for 10.3% of the tested materials. Resistant material 25, accounting for 64.1%, light resistant material 10, accounting for 25.6%, there is no completely immune and susceptible materials.2. chilling stress 3 Watermelon Resistant Rootstock Seedlings Growth was inhibited and the chilling injury rate and chilling injury index increased significantly, 10d low temperature treatment, 3 watermelon rootstocks chilling injury rate reached 100%. at low temperature stress significantly inhibited the 'BEH * Ag2-1', 'BYH * FR328' and 'BEH * FR328' rootstock plant height, stem diameter, leaf area and leaf number increased, significantly reduced the total dry matter accumulation and distribution of rootstocks, combined with morphological observation, "BEH 脳Ag2-1鈥欏彾鐗囪竟緙樿交搴﹁悗钄，

本文編號：1734755