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1.
大丽轮枝菌蛋白激发子PevD1诱导棉花抗病性及作用机理   总被引：3，自引：0，他引：3  
 PevD1是一种大丽轮枝菌(Verticillium dahliae)分泌蛋白,具有激发烟草过敏反应(HR)和系统获得性抗病(SAR)的功能。为明确蛋白PevD1诱导棉花抗病性及其作用机制,本文利用大肠杆菌表达、纯化的PevD1诱导棉苗植株,检测棉苗对大丽轮枝菌的抗性及免疫应答反应。结果表明,大肠杆菌表达的PevD1重组蛋白不是棉花品种“新陆早42号”的致萎因子,叶片注射8 μg/mL PevD1蛋白诱导3 d后根部接种大丽轮枝菌,15 d后PevD1处理组病害减轻率达35.04%。PevD1能诱导棉花叶片抗性早期信号分子H2O2产生和NO积累,维管束细胞壁加厚、木质素和酚类物质的积累。另外,PevD1处理能提高防御酶PAL、POD和PPO活性,提高棉花抗性基因和木质素合成相关基因PAL、C4H1、4CL的转录水平。说明PevD1通过激发棉花免疫系统而提高抗病性,该研究不仅为利用PevD1蛋白激发子控制棉花黄萎病提供了科学依据,同时也为阐明棉花与大丽轮枝菌互作机理提供了理论基础。  相似文献   

2.
The potato leafroll virus (PLRV) P0 protein (P0PL) is a suppressor of RNA silencing. In this study, we showed that P0 protein from an Argentinian isolate of PLRV (P0PL-Ar) has an additional activity not described for other PLRV or P0 proteins from poleroviruses. Besides reporting that P0PL-Ar displays both local and systemic silencing suppressor activity, we demonstrated, for the first time, that P0PL-Ar impedes accumulation of dsRNA-derived siRNAs. We also showed that P0PL-Ar interacts with Solanum tuberosum SKP1 orthologue (StSKP1) and triggers destabilization of ARGONAUTE 1 (AGO1) and that these actions are mediated by the F-box-like domain. A mutant in the GW/WG motif within the P0PL-Ar F-box-like motif lost the suppression activity, the interaction with StSKP1 and abolished AGO1 decay. Interestingly, a mutant in the L76/P77 residues within the P0PL-Ar F-box-like motif, which lost the suppression activity and the interaction with StSKP1, retained the capacity to enable AGO1 decay. Thus, unlike other P0 proteins of previously characterized poleroviruses, P0PL-Ar seems to have a dual activity, according to the findings of this study. This protein would act at both an upstream and a downstream step of the RNA silencing pathway: upstream of Dicer-like enzyme (DCL)-mediated primary siRNA production and downstream at the RNA-induced silencing complex (RISC) complex level. Our results contribute to the understanding of the different ways PLRV P0 proteins function as silencing suppressors.  相似文献   

3.
Twenty-two cotton varieties were screened for resistance to cotton leaf curl disease (CLCuD), a disease of viral origin, using three procedures: field evaluation, whitefly transmission assay and graft inoculation. Viral infection of cotton varieties was determined by visual symptom assessment as well as dot-blot and multiplex PCR diagnostic techniques. Crosses were made between the most susceptible variety (S-12) and highly resistant varieties (CP-15/2, LRA-5166 and CIM-443). All F1 plants of these crosses were resistant, showing dominant expression of the resistance as well as the absence of extrachromosomal inheritance. The F2 plants of the crosses CP-15/2 × S12, LRA-5166 × S-12 and CIM-443 × S12 exhibited a ratio of 13 resistant (symptomless) to three susceptible (with symptoms). Screening of the F2 generation for virus infection by multiplex PCR further subdivided the resistant class into those exhibiting a high level of resistance (HR; PCR-negative) and those exhibiting resistance (R; symptomless, yet showing virus replication by PCR analysis). Hence, the final ratio was 3:10:3 (HR:resistant:susceptible). The F3 progeny of susceptible F2 plants segregated for resistance, indicating the probable presence of a suppressor gene ( S ). These findings are consistent with three genes being involved in G. hirsutum resistance to CLCuD, two for resistance ( R 1CLCuDhir and R 2CLCuDhir ) and a suppressor of resistance ( S CLCuDhir ).  相似文献   

4.
为明确三氟啶磺隆与精喹禾灵混用的联合除草作用及其对棉花的安全性,采用温室盆栽生物测定法,测定了其对香附子、马唐、牛筋草、马齿苋和反枝苋的联合除草作用,并对不同品种棉花的安全性及其在棉花与杂草之间的选择系数进行了研究。结果显示:三氟啶磺隆与精喹禾灵混用对香附子、马齿苋的防除效果为加成或增效作用,对马唐、牛筋草和反枝苋则以加成作用为主。当m(三氟啶磺隆)∶m(精喹禾灵)=1∶3和1∶4时,有效成分80 g/hm2的处理对供试棉花品种均安全,而有效成分160 g/hm2处理则对不同棉花安全性差异较大,其中对山农棉8号鲜重的抑制率较高,对鲁棉研36号则较安全;两者复配剂在棉花与杂草间的选择系数明显高于三氟啶磺隆单剂,提高了三氟啶磺隆对棉花的安全性。  相似文献   

5.
棉花抗蚜性与可溶性糖含量的关系   总被引：4，自引：1，他引：3  
为探讨可溶性糖含量与棉花抗蚜性的关系,在室内人工接蚜为害和田间自然蚜群两种条件下,测定不同抗蚜性棉花品种受棉蚜为害后叶片中可溶性糖含量及其对棉蚜生长发育和繁殖的影响。结果表明:未受棉蚜为害时,抗性品种中可溶性糖含量高于感性品种,棉蚜为害胁迫后,抗蚜棉花品种可溶性糖含量升高,感蚜品种的可溶性糖含量降低。棉蚜的生长发育和繁殖与棉花叶片中可溶性糖含量呈显著的相关,可溶性糖与棉蚜若蚜历期呈正相关,与内禀增长率呈负相关。本研究说明可溶性糖含量对棉花的抗蚜性有一定的影响,转基因棉可溶性糖含量低于常规棉品种可能是导致非目标害虫棉蚜猖獗的原因之一。  相似文献   

6.
Clomazone may be safely used in cotton to manage weeds when applied following treatments of the organophosphate insecticides phorate or disulfoton. The loss of chlorophyll and carotenoids with 6 days of 100 nM clomazone treatment of cotton seedlings was partially prevented with phorate in hydroponic solution in a rate-dependent manner. In a study to examine the timing of safening from a one-day clomazone (100 nM) treatment, maximum safening was achieved when phorate (50 μM) was applied the same day as clomazone. Phorate decreased metabolism of 14C-clomazone to polar metabolites in excised cotton shoots and shoots of intact cotton plants. Microsomal studies of corn shoots showed an NADPH-dependent/cytochrome P450 reaction was inhibited by phorate. Additional studies with corn microsomes, corn seedlings and cotton seedlings supported the basis of clomazone safening is the inhibition of toxic clomazone metabolism by P450 inhibitors.  相似文献   

7.
成团泛菌引起的棉花烂铃病对棉花产量因子和品质的影响   总被引：5，自引：1，他引：4  
成团泛菌(Pantoea agglomerans)引起的棉花烂铃病主要造成棉铃吐絮不畅,棉纤维变色,籽粒干瘪。本试验对感染该病害的不同棉花品种的发病率、绒长、单铃重、衣分以及色泽等指标进行测定,用SAS软件分析,结果显示:所有棉花品种都有烂铃病的发生,平均发病率为20.6%,不同品种间发病有明显的差别。病害对单铃重、衣分、瘪籽率、绒长及色泽的影响主要体现在单铃重平均减轻27.6%、衣分平均降低5.3%和瘪籽率平均增加1.6倍、绒长平均缩短1.6mm及平均颜色加深2.0%。由成团泛菌引起的这种细菌病害可引起棉花减产高达10%～20%。  相似文献   

8.
为明确我国主要棉花品种对木尔坦棉花曲叶病毒(Cotton leaf curl Multan virus,CLCuMuV)的抗性水平,采用烟粉虱田间自然传毒和CLCuMuV侵染性克隆人工接种方法分别对收集的46个棉花品种进行抗性鉴定。结果显示:46个棉花品种田间播种后90 d,新海21号、新海31号、新37号及112-2号4个品种自然发病的病株率为41.70%~100.00%,病情指数为39.81~100.00;新陆早36号、新陆中52号、中棉35号、中棉43号、鲁棉研36号、金宏祥10号6个品种的病株率为8.30%~16.70%,病情指数为0.93~9.26;其余品种未见发病。46个棉花品种人工接种CLCuMuV后60 d,新海21号、新海31号、新海37号和112-2号4个品种的病情指数为75.00~100.00,表现为高感;新陆中66号和新陆早46号病情指数分别为20.83和20.37,表现为中感;新陆早62号等10个品种的病情指数为10.46~15.87,表现为中抗;新陆早47号等14个品种的病情指数为5.26~9.26,表现为抗病;豫棉15号等11个品种的病情指数为2.22~4.86,表现为高抗;新陆早13号、新陆早61号、新陆中32号、新陆中56号和中棉41号病情指数均为0,表现为免疫。  相似文献   

9.
为明确丙炔氟草胺与二甲戊灵复配的联合除草作用及其对棉花的安全性,采用室内生物测定方法,研究了复配制剂的联合除草类型,测定了其对不同品种棉花的安全性及其在棉花与杂草之间的选择性指数,并对复配制剂进行田间药效试验。温室试验结果显示:丙炔氟草胺与二甲戊灵按不同质量比复配后,对供试杂草马齿苋、反枝苋和马唐均呈现加成或增效作用。其中丙炔氟草胺与二甲戊灵按质量比1 : 10复配后的除草活性高于二甲戊灵单剂,其在供试棉花品种与供试杂草的选择性指数在25.81~39.39之间,与两种单剂相比,在一定程度上提高了对棉花的安全性。田间药效试验结果显示:丙炔氟草胺与二甲戊灵复配后综合了两种单剂的优势,对铁苋菜、反枝苋、马齿苋、藜和牛筋草均有很好的防除效果且对棉花安全。  相似文献   

10.
以4个品种转Bt基因抗虫棉及其对照常规棉为研究对象，采用ELISA试剂盒法检测其在不同生育期根际土壤Bt蛋白残留，同时比较速效养分含量的变化。结果表明：（1）棉花根际土壤中Bt蛋白的残留量在蕾期达到最大；在整个生育期4个品种转基因抗虫棉根际土壤中Bt蛋白的含量均显著高于对照常规棉（P＜0.05），其中鲁棉研28号在蕾期显著高于对照常规棉1 029.66%，鲁棉研36号在蕾期显著高于对照常规棉2 573.45%，山农棉8号在苗期显著高于对照常规棉1 208.89%，鑫秋4号在花铃期显著高于对照常规棉793.18%。（2）棉花根际土壤中硝态氮含量在苗期最高，吐絮期最低，且在部分生育期转基因抗虫棉与对照常规棉差异显著；铵态氮含量在苗期最高，吐絮期最低，4个品种转基因抗虫棉在蕾期、花铃期均与对照常规棉差异显著；速效磷含量在苗期最低，吐絮期最高，其中鲁棉研28号在蕾期显著高于对照常规棉10.29%，鲁棉研36号在苗期显著高于对照常规棉6.77%。研究表明，转基因抗虫棉的种植和生育期是影响棉花根际Bt蛋白残留量、速效养分含量的主要因子。  相似文献   

11.
Abstract

Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum (Atk.) Sny. & Hans. is an important disease of cotton in several developing countries where the use of resistant varieties continues to be the most practical method of control. The inheritance of resistance to wilt is complex, involving several major and minor genes. In order to identify resistant genotypes in segregating populations large numbers of plants must be screened using inoculation methods which minimise disease escape. Wilt incidence is increased when plants are attacked by the rootknot nematode (Meloidogyne acrita Chitwood, 1949) Esser et al. 1976. In areas where both organisms occur together, the wilt resistance‐potential of a variety cannot be realised unless it also has resistance to root‐knot. Problems of breeding for wilt resistance are discussed with reference to Tanzania, and methods are described for their application to a wilt‐resistance programme.  相似文献   

12.
喷施外源激素对棉株棉花黄萎病发病程度的影响   总被引：3，自引：0，他引：3  
通过温室人工接菌 ,研究了喷施 4种外源激素 3-吲哚乙酸、赤霉素、脱落酸和反 -玉米素对棉苗棉花黄萎病发病程度的影响。结果表明赤霉素在5.0～80.0μg/ml浓度范围内 ,提高了棉苗抗病性 ,但棉苗表现徒长、叶片畸形 ;反 -玉米素25.0～80.0μg/ml明显促进了病情发展 ;3-吲哚乙酸10μg/ml,脱落酸0.5μg/ml,反 -玉米素10 μg/ml的处理对降低棉苗的发病率和发病程度作用较明显。  相似文献   

13.
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14.
Root-knot nematode [RKN] (Meloidogyne incognita) can increase the severity of Verticillium (V. dahliae) and Fusarium (F. oxysporum f.sp.vasinfectum) wilt diseases in cotton (Gossypium hirsutum). This study was conducted to determine some of the physiological responses caused by nematode invasion that might decrease resistance to vascular wilt diseases. The effect of RKN was investigated on spore germination and protein, carbohydrate and peroxidase content in the xylem fluids extracted from nematode-infected plants. Two cotton cultivars were used with different levels of resistance to both of the wilt pathogens. Spore germination was greater in the xylem fluids from nematode-infected plants than from nematode-free plants. The effect on spore germination was greater in theFusarium-resistant cultivar (51%). Analysis of these fluids showed a decrease in total protein and carbohydrate levels for both wilt-resistant cultivars, and an increase in peroxidase concentration. Fluids from nematode-free plants of theVerticillium-resistant cultivar contained 46% more peroxidase than theFusarium-resistant cultivar. The results provide further evidence that the effect of RKN on vascular wilt resistance is systemic and not only local. Changes in metabolites in the xylem pass from the root to the stem, accelerating disease development.  相似文献   

15.
A survey of cotton (Gossypium hirsutum) volunteers was conducted along the 1400 km of a cottonseed transport route in north‐east Australia to determine the extent of naturalisation from spilt seed. In each year, 1% of the road distance was inspected for volunteer plants. The survey results were juxtaposed with the eco‐climatic suitability predictions from inferential modelling. Over 3 years, 22 cotton plants were found at eight sites. Within the cotton production region, volunteers averaged 2.28 plants km−1 of road; their most likely source was seed cotton spilt during the previous harvest. Further north, three plants were found over 3 years, at an average density of 0.089 plants km−1 of road; all three plants were found in locations with a positive Ecoclimatic Index. No secondary spread was detected. Roadside slashing reduced plant survival and the potential to produce seed. In the wet tropics, weed competition and slashing prevented volunteers establishing. The surveys indicate that roadsides in north‐east Australia are a hostile environment for the establishment of cotton plants, with no evidence of naturalisation or secondary spread. Current transport practices utilizing fully covered loads present negligible risk of producing naturalised populations of cotton (either transgenic or non‐transgenic) on roadsides in north‐east Australia.  相似文献   

16.
RNA silencing is one of the conserved antiviral mechanisms in plants, and viruses encode RNA silencing suppressors (RSS) to overcome host RNA silencing and facilitate virus infection. Sugarcane streak mosaic virus (SCSMV; species Sugarcane streak mosaic virus, genus Poacevirus, family Potyviridae) is a major causal agent of sugarcane mosaic disease in many countries in Asia, including China. In this study, we used Agrobacterium co-infiltration to show that the SCSMV P1 protein, rather than the helper component-proteinase (HC-Pro), functions as a strong RSS to suppress local RNA silencing in Nicotiana benthamiana. Mutational analysis indicated that the 15 amino acids (aa; aa 1–15) of the SCSMV P1 N-terminus were not important for RNA silencing suppression, but rather another 15 aa domain (aa 108–122) containing a conserved motif (LFR/KNKQAYIST) was essential for efficient silencing suppression by P1. In addition to the 15 aa (aa 344–358) domain in the P1 N-terminus, another 15 aa domain (aa 65–79) of P1, containing the LXKA motif and one conserved aa (D78), were associated with P1 protein stability. Furthermore, substituting the histidine (H263) residue in P1 with threonine (H263T) or alanine (H263A) also affected P1 protein stability. Notably, the H263 residue is both a positively selected site and part of the serine protease catalytic triad (HDS). Taken together, our data demonstrate that SCSMV P1, and not HC-Pro, plays a functional role in suppressing RNA silencing, and also show that some conserved motifs and a positivelyselected site in the P1 protein are associated with RSS activity and protein stability.  相似文献   

17.
A rapid glasshouse‐based bioassay method to screen large numbers of cotton plants for responses to Fusarium oxysporum f. sp. vasinfectum (Fov) was developed. Different Fov inoculum concentrations and methods of inoculation were assessed using resistant and susceptible cotton cultivars. Cotton seeds were planted directly into Fov‐inoculated soil. Studies of seed germination, seedling establishment, seedling mortality and fusarium wilt symptoms (i.e. stunting, foliar symptoms and vascular browning) were performed to optimize the bioassay parameters. Growing seedlings in Fov‐inoculated soils at 5 × 104 or 1 × 105 CFU g?1 soil, in individual seedling tubes with 12 h at 28–30°C and 12 h at 15–18°C, gave consistent results when assessing Fov disease responses 6 weeks after inoculation. When fusarium wilt resistance ranks (FWRRs) and vascular browning index (VBI) means of 18 Australian and other cotton cultivars from the Fov glasshouse bioassay were compared against their fusarium field performance ranks (F‐ranks), assessed on adult plants for cotton cultivar release, Pearson’s correlation was highly significant for both comparisons. The level of congruence between field and glasshouse data indicated that this protocol should be an effective tool for large‐scale screening for Fov‐resistance responses in diverse germplasm and breeding populations and for advancing genetic research to develop molecular markers for Fov resistance in cotton.  相似文献   

18.
Bacillus thuringiensis cotton is a variety of cotton genetically modified to contain a gene derived from B. thuringiensis bacteria; which results in expression of toxin protein that confers resistance to bollworm complex (the most destructive pest of cotton). Introduction of Bt cotton lowered the need of insecticides, but still a number of insecticides are used for other insects like jassids, whitefly, aphids and tobacco caterpillar to which Bt gene does not provide effective control. Imidacloprid (tradename Imidacel 17.8 SL) is an insecticide designed for control of these major sucking/piercing insects that affect cotton. So in the present work we studied the post effect of imidacloprid insecticide on plant health of three Bt cotton hybrids (RCH-134, JKCH-1947, NCEH-6R) as there are reports of this insecticide causing growth and yield enhancements in absence of insect pests. Imidacloprid was first sprayed at recommended concentration (40 ml/acre) on 3 months old plants sown in randomly designed plots with three replications of each hybrid. The spray was repeated three times at 10 days interval. The level of B. thuringiensis gene expression, peroxidase activity and total phenols was measured on third day after every spray in leaves along with growth and yield of plants. The insecticide has shown to increase the level of B. thuringiensis protein, peroxidase enzyme activity, total phenols, height, number of bolls retained on plants and yield. These observations suggested that the imidacloprid treated plants showed better growth and development, thereby imidacloprid has growth enhancing effect on Bt cotton plants in addition to its insecticidal properties.  相似文献   

19.
选用新海24号和新海36号为试验材料,研究花铃期3 900、3 150、2 400 m3·hm-2等不同滴灌水平对海岛棉产量形成的影响。结果表明:叶面积指数(LAI)、净光合速率(Pn)、叶绿素SPAD值、干物质积累表现为3900 m3·hm-2处理较高,3 150 m3·hm-2次之,2 400 m3·hm-2较低;棉铃脱落率呈相反趋势,即2 400 m3·hm-2滴灌处理3 150 m3·hm-2滴灌处理3 900 m3·hm-2滴灌处理;滴灌水平3 900 m3·hm-2处理的皮棉产量为2228.49 kg·hm-2,比3 150、2 400 m3·hm-2处理分别高36.68%、49.38%。品种对各滴灌水平响应不同,不同滴灌处理下的LAI、干物质积累和棉铃脱落率为新海24号新海36号,而新海24号的Pn、SPAD值、皮棉产量高于新海36号。因此,花铃期滴灌水平3 900 m3·hm-2条件下有利于实现海岛棉高产。  相似文献   

20.
A boll rot of cotton (Gossypium hirsutum L.) was observed for the first time in Greece in August 1993 in Larissa and Volos counties, and in August and September 1995 in Trikala and Phthiotis counties. Fungi of the genusPhytophthora were isolated from diseased plants. Morphological characteristics of the pathogen were recorded on mounts made directly from the infected tissues or after growth of the isolated fungus on corn meal agar or sterile distilled water. Colony morphology, growth rates, features of asexual and sexual structures and maximum growth temperatures were examined. APhytophthora species new to Europe,Phytophthora boehmeriae Sawada, attacking cotton bolls, was identified. The pathogenicity of the isolates was confirmed by artificial inoculations of detached cotton bolls. Analysis of α-esterase isozymes revealed unique banding patterns for isolates ofP. boehmeriae compared with those ofP. cactorum andP. parasitica, which arePhytophthora species with similar morphology.  相似文献   

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