【摘要】：目的:明確石河子地區(qū)菟絲子種類、生物學特性并篩選出對菟絲子強致病的生防菌株及高效化學藥劑,為新疆菟絲子的防治提供理論和技術支持。方法:從石河子市內及其周邊采集菟絲子莖、花和種子,采用形態(tài)學與分子生物學(ITS、rbc L、trn L-F序列分析)對其進行鑒定;通過盆栽試驗和田間觀察,掌握石河子地區(qū)主要種單柱菟絲子和田野菟絲子菟絲子的生物學特性及發(fā)生規(guī)律;采集自然發(fā)病的菟絲子病樣,進行組織分離,致病性測定、形態(tài)學及分子生物學鑒定;對獲得的分離物進行強致病菌株的篩選,并對篩選獲得的強致病菌株進行了生物學特性研究和田間防效測定;采用不同濃度噴灑試驗在小區(qū)篩選高效防治化學藥劑。結果:1、從石河子地區(qū)共采集了37份菟絲子樣品,并將其鑒定為兩個種:田野菟絲子Cuscuta.campestris和單柱菟絲子Cuscuta.monogyna。其中田野菟絲子大部分寄生在草本植物上,單柱菟絲子既能寄生木本植物,又能寄生在草本植物上。2、種子吸水率試驗結果說明:2種菟絲子大部分種子種皮不透水,種子具有物理休眠特性;單柱菟絲子劃破種子在-4-35℃均能發(fā)芽,在30℃時,總萌發(fā)率為最高。田野菟絲子劃破種子在溫度低于10℃時不萌發(fā),在25℃時,總萌發(fā)率為最高。25℃時,兩種菟絲子芽長均為最長;不同光照條件對單柱菟絲子和田野菟絲子種子的最終萌發(fā)率和芽長均無顯著影響,但在不同光照條件下單柱菟絲子嫩芽的顏色存在差異,在持續(xù)光照和光暗交替(16/8 h)條件下呈淺紫色,持續(xù)黑暗條件下呈白色(無色),持續(xù)暗光條件下呈淡黃色。不同光照條件對田野菟絲子嫩芽顏色均無顯著影響;當土壤含水量為30%時,單柱菟絲子和田野菟絲子的萌發(fā)率和芽長均達到最高值。3、菟絲子種子在4月下旬至5上旬連續(xù)的春雨后,開始大量萌發(fā)出土,6月份至8月份開花。單柱菟絲子和田野菟絲子結果到果實成熟分別需要40 d和20 d左右。4、采集了159份菟絲子病樣并將其歸類為三種典型癥狀,進行組織分離獲得123個分離物。經(jīng)致病性測定獲得96個致病菌,其中交鏈格孢菌Alternaria alternata為優(yōu)勢種,共62個,占致病菌的64.5%;不等彎孢菌Curvularia inaequalis 13個,占13.5%;金黃殼囊孢菌Cytospora chrysosperma 2個,占2.08%;串珠鐮刀菌Fusarium verticillioides17個,占17.7%;其他2個,占2.08%。經(jīng)過離體接種和小區(qū)試驗,篩選出3株致病性較強的致病菌,即交鏈格孢菌k4-1,串珠鐮孢菌m5和不等彎孢菌d1-3。這3株致病菌的懸浮液處理寄生在榆樹上的單柱菟絲子后,發(fā)現(xiàn)15 d均能使菟絲子死亡,防效可以達到100%。5、單柱菟絲子的4株高效生防菌株k4-1、d1-3、m5和腐爛病菌株y2-3的菌絲適宜生長的溫度范圍為25-30℃,最適菌絲生長的溫度為25℃。菌株m5分生孢子在25℃萌發(fā)率最高,菌株k4-1和d1-3在30℃萌發(fā)率為最高;菌株k4-1、d1-3和m5孢子萌發(fā)率隨相對濕度增加而增大;菌株d1-3、k4-1、m5和y2-3菌絲在p H值為4-12時均能生長,菌株m5適宜菌絲生長p H值范圍為7-11,菌株d1-3和k4-1適宜菌絲生長p H值范圍為5-10,菌株y2-3適宜菌絲生長p H值范圍為4-6。適宜菌株k4-1、d1-3和m5孢子萌發(fā)p H值范圍為6-9。以上4種菌株對菟絲子常見寄主安全性測定結果表明,4種菌株對無傷口寄主苦豆子、月季、榆樹、丁香和赤楠等均安全,無致病性。6、41%草甘膦異丙胺鹽AS 410、820 mg/L、10.8%精喹禾靈EC 67 mg/L、苯·唑·2甲鈉275 mg/L對菟絲子防效高,對寄主榆樹安全,效果較為理想。
文內圖片：
圖片說明：菟絲子種子形態(tài)特征(A，田野菟絲子；B，單柱菟絲子)
[Abstract]:Objective: To study the species and biological characteristics of the sericin in Shihezi area and to screen the biocontrol strains and high-efficiency chemical agents which are highly pathogenic to the silk and to provide the theoretical and technical support for the prevention and treatment of the sericin in Xinjiang. Methods: The stem, flower and seed were collected from the city of Shihezi and its surroundings. The morphology and molecular biology (ITS, rbc L, trn L-F sequence analysis) were used to identify them. To master the biological characteristics and the law of the main species of the single-column and the field-type silk and silk in the Shihezi area, and to collect the disease-like samples of the natural disease, to conduct tissue separation, pathogenicity measurement, morphology and molecular biology identification; The obtained isolate is screened for strong pathogenic bacteria, and the biological characteristic research and field control effect measurement are carried out on the strong pathogenic bacteria strain obtained by screening; and the chemical agent is effectively and effectively prevented from being screened in a cell by using different concentration spraying tests. Results:1. A total of 37 samples were collected from Shihezi area and identified as two species. In that field, most of the grass of the field of the field is parasitic on the herb, and the single-column filament is not only parasitic on the woody plant, but also can be parasitic on the herb. The results showed that the germination rate was the highest at the temperature of-4-35 鈩

本文編號：2511324