【摘要】：糜子生育期短、抗旱、耐瘠、營養(yǎng)豐富,是干旱半干旱地區(qū)重要的糧食作物和經(jīng)濟作物。絲黑穗病是糜子生產(chǎn)上的主要病害,是制約糜子產(chǎn)量和品質(zhì)的重要因素。因此,分析病原菌遺傳多樣性水平和毒力分化程度,研究糜子絲黑穗病抗性生理機制,篩選高效防治藥劑,明確適宜栽培措施,對抗病品種選育及病害綠色防控具有十分重要的意義。由于糜子屬區(qū)域性作物,目前國內(nèi)外關(guān)于糜子及糜子絲黑穗病的相關(guān)研究鮮有報道,本試驗利用RAPD和SSR分子標記技術(shù)對來自我國糜子主產(chǎn)區(qū)的病原菌進行遺傳多樣性分析,鑒定糜子種質(zhì)資源和育成品種絲黑穗病抗性水平,篩選鑒別寄主并對病原菌進行毒力分析,比較分析糜子不同生育時期感染絲黑穗病后葉片抗氧化酶系、抗病相關(guān)酶活性,蛋白質(zhì)、糖含量,及同工酶譜帶的變化和差異,通過室內(nèi)毒力測定和田間藥效試驗,篩選防治糜子絲黑穗病高效殺菌劑,并且研究不同播期對抗、感品種絲黑穗病發(fā)病及產(chǎn)量的影響。主要研究結(jié)論如下:(1)田間調(diào)查結(jié)果顯示,糜子絲黑穗病為害的穗部癥狀主要表現(xiàn)為黑粉包狀、簇葉狀、刺猬頭和黑粉粒4種類型。糜子絲黑穗病菌冬孢子在光學(xué)顯微鏡下,呈褐色,球形,掃描電子顯微鏡下可見壁表具微小突起。冬孢子形態(tài)特征和ITS序列比對結(jié)果表明,本試驗所用菌株為Sporisorium destruens。冬孢子萌發(fā)的最適溫度為25℃,最適pH為5,甲醛處理促進萌發(fā)。絲黑穗病菌最適碳源和氮源為葡萄糖和KNO3,25℃比較適合此病菌生長和產(chǎn)孢,pH為7時生長最快、產(chǎn)孢量最大,在Czapek和PDA培養(yǎng)基上生長較好。(2)來自我國黑龍江、吉林、遼寧、內(nèi)蒙古、河北、陜西和甘肅的糜子絲黑穗病菌(S.destruens)遺傳變異程度不高,遺傳背景比較單一。選出的28條RAPD引物和40對SSR引物分別擴增出381和119條譜帶,其中多態(tài)性譜帶373和109條,多態(tài)率分別為97.90%和91.60%。RAPD的多態(tài)性水平及檢測效率高于SSR。兩種標記的聚類結(jié)果有差異。將兩種標記的數(shù)據(jù)結(jié)合進行聚類,結(jié)果顯示,在遺傳相似系數(shù)為0.7425時,51個菌株可以分為3個系譜群。菌株的遺傳多態(tài)性和地理分布及寄主品種之間沒有明顯的相關(guān)性。(3)連續(xù)3年絲黑穗病抗性鑒定結(jié)果顯示,261份種質(zhì)資源的抗性差異明顯,抗病種質(zhì)所占比重較大,其中12MD-2和12MD-250連續(xù)3年均表現(xiàn)免疫;66份育成品種中,來自俄羅斯的品種blest jachee和orlovski karlik表現(xiàn)高抗,而我國的品種均未表現(xiàn)出穩(wěn)定抗性。參試糜子種質(zhì)資源中,3份具有高抗、矮稈、早熟和高產(chǎn)等優(yōu)良性狀,可直接用于實際生產(chǎn)。我國S.destruens存在毒力分化現(xiàn)象,根據(jù)各鑒別寄主對各菌株的抗性等級,可將16個菌株分為3個致病類型。(4)糜子接種S.destruens后,SOD活性升高,三葉期抗病品種的升高幅度顯著大于感病品種,且抗病品種的SOD活性顯著高于感病品種;抗病品種POD活性持續(xù)升高,而感病品種POD活性在后期下降;抗病品種MDA含量低于感病品種。糜子受S.destruens侵染后,抽穗期和灌漿期APX活性與抗性呈負相關(guān);GR活性與抗性成反比;抗病品種AsA含量迅速升高并維持在較高水平,而感病品種升高較慢且后期下降幅度較大;抗、感品種GSH含量在三葉期和拔節(jié)期升高,在抽穗期和灌漿期下降。在S.destruens誘導(dǎo)下,抗病品種PAL活性升高幅度在三葉期、拔節(jié)期和灌漿期均高于感病品種,三葉期和拔節(jié)期抗病品種幾丁質(zhì)酶活性顯著高于感病品種,β-1,3-葡聚糖酶活性在抽穗期與抗性呈正相關(guān)。接種后,可溶性蛋白含量與發(fā)病率無顯著相關(guān)性;在三葉期和灌漿期可溶性總糖含量與抗性呈負相關(guān);而還原糖含量在三葉期和拔節(jié)期接種后與抗性呈負相關(guān)。絲黑穗病菌侵染能引起不同抗病類型糜子品種POD、EST、SOD和PPO同工酶譜的變化,抗病品種譜帶增加數(shù)大于感病品種。綜上,在糜子抗病育種和生產(chǎn)實踐中,SOD、POD、APX、GR、PAL、幾丁質(zhì)酶和β-1,3-葡聚糖酶活性,MDA、AsA、GSH、可溶性總糖及還原糖含量,POD、EST和SOD同工酶均可作為鑒別糜子絲黑穗病抗性的輔助指標。(5)通過對戊唑醇、甲基硫菌靈、烯唑醇、多菌靈、苯醚甲環(huán)唑和福美雙6種藥劑的室內(nèi)毒力測定和兩年田間藥效試驗,結(jié)果發(fā)現(xiàn),戊唑醇對冬孢子萌發(fā)的抑制作用最強,福美雙最弱;烯唑醇對種子萌發(fā)抑制作用最大;戊唑醇田間防效最好,其次為烯唑醇、甲基硫菌靈、多菌靈,福美雙防治效果最差。多菌靈顯著降低主莖倒二葉面積、主莖倒三葉面積、葉干重和分蘗數(shù),各藥劑處理下的單株粒重均有不同程度的減少,但產(chǎn)量均增加,其中戊唑醇處理下的產(chǎn)量兩年均最高。戊唑醇能以較低濃度獲得較好的防治效果,建議在實際生產(chǎn)中推廣利用。(6)不同糜子品種對播期的響應(yīng)不同,但除05在5個播期均不發(fā)病外,其他品種均在播期Ⅰ發(fā)病率最高,其他播期無顯著差異�？共∑贩N巴盟小黑糜和05在播期Ⅲ產(chǎn)量最高,因此6月15日左右可作為這兩個品種的適宜播期;感病品種雜黍和黃硬糜在播期Ⅱ產(chǎn)量最高,因此可將6月1日作為這兩個品種的適宜播期。發(fā)病率和5 cm土層溫度呈顯著負相關(guān),低溫有利于絲黑穗病的發(fā)生;發(fā)病率與20 cm土層水分含量無顯著相關(guān)性。
[Abstract]:The millet has the advantages of short growth period, drought resistance, drought tolerance and rich nutrition, and is an important food crop and economic crop in the arid and semi-arid region. The main disease in the production of mylis is the main disease which restricts the yield and quality of the mylin. Therefore, it is of great significance to study the genetic diversity of pathogenic bacteria and the degree of virulence differentiation, to study the physiological mechanism of the resistance to the black-ear disease of mylin, to select the effective control agent, to identify the appropriate cultivation measures, and to have a very important significance to the breeding of the disease-resistant variety and the prevention and control of the disease. In the present study, the genetic diversity of the pathogenic bacteria from the main production areas of the Myli in China was analyzed by using the RAPD and SSR molecular markers. in that invention, the resistance level of the millet germplasm resource and the black spike of the bred variety is identify, the host is screened and the virulence analysis is carried out on the pathogenic bacteria, the anti-oxidation enzyme system, the disease-related enzyme activity, the protein and the sugar content of the leaf after the different growth period of the millet are compared and analyzed, And the effect of different sowing time on the incidence and the yield of the black-ear diseases of the variety silk is studied through the indoor toxicity measurement and the field effect test. The main results of the study are as follows: (1) The results of the field investigation show that the symptoms of the ear part of Mylin black are mainly in the form of black powder, cluster-leaf shape, hedgehog head and black powder. The microprojections of the wall surface were observed under the optical microscope, in the form of brown, spherical and scanning electron microscope. The results of the comparison of the morphological characteristics and the ITS sequence of the winter spore show that the strain used in this test is Sporisoria dessenens. The optimum temperature of the winter spore germination was 25 鈩，

本文編號：2485472