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191.
Ming Pei You Beyene Bitew Eshete Seid Ahmed Kemal Joop van Leur Martin J. Barbetti 《Plant pathology》2021,70(5):1180-1194
Faba bean gall (FBG) is a devastating disease of faba bean (Vicia faba) in Ethiopia. Studies were undertaken first to compare and contrast similarities between FBG disease symptoms and morphology in Ethiopia with those reported earlier in China and, secondly, to identify definitively the FBG causal agent, previously considered as Olpidium viciae, through molecular studies. Morphological studies confirmed an epibiotic phase of zoosporangia for dispersing zoospores, characteristic of Physoderma but not Olpidium, and did not show critical diagnostic characteristics of Olpidium such as presence of numerous short zoosporangial discharging tubes, or binucleate resting sporangia. Recognizing this epibiotic phase is a foundation for comprehending FBG epidemiology and will allow forecasting of zoospore release to highlight best timings for applications of chemical sprays to reduce reinfection cycles. Sequences of partial ITS1-5.8S-partial ITS2, the 18S-ITS1-5.8S-ITS2-part of 28S rRNA, and LSU (28S rRNA) derived from tissue with symptoms confirmed Physoderma, and not Olpidium, as the causal agent. Sample sequences were either close to Physoderma or the contaminant ascochyta pathogen Didymella. From symptom, morphological, and molecular data, the causal agent of FBG disease in Ethiopia is Physoderma. From observations of symptoms that Physoderma can cause, it was determined that this Physoderma crosses over between different legume host genera (e.g., Vicia, Pisum, Trifolium), highlighting the significant biosecurity risk for countries currently free of FBG. 相似文献
192.
Dawelbeit Ahmed Hongpeng Zhong Haijuan Kong Jing Liu Yu Ma Muhuo Yu 《Fibers and Polymers》2014,15(9):1850-1854
Poly(p-phenylene terephthalamide) fibers prepared by dry-jet wet spinning processes have a notable response to very brief heat treatment (seconds) under tension. The modulus of the as-spun fiber can be greatly affected by the heat treatment conditions (temperature, tension and duration). The crystallite orientation and the fiber modulus will increase by this short-term heating under tension. The present research reports the heat treatment techniques, devices and its process conditions. It reports in details the structural relationships between the fiber properties which are influenced by the heat treatment process. In particular, focuses deeply on the effect of the crystal orientation changes of the fibers, on the mechanical properties and, also, investigates the thermal degradation steps & behaviours of the heat treated fibers. The heat treated PPTA fibers have a molecular orientation higher than that for the as-spun one. 相似文献
193.
Shahriar Saleh Ahmed Nur-Shakirah Abdul Omar Mohd Masratul Hawa 《European journal of plant pathology / European Foundation for Plant Pathology》2022,162(3):709-724
European Journal of Plant Pathology - Tea (Camellia sinensis) is a popular and extensively consumed beverage in Malaysia along with many other countries around the world. Grey blight is one of the... 相似文献
194.
Abdul Latif Khan Muhammad Waqas Javid Hussain Ahmed Al-Harrasi In-Jung Lee 《Biology and Fertility of Soils》2014,50(1):75-85
We investigated the role of gibberellins-producing endophyte Penicillium janthinellum LK5 associated with Solanum lycopersicum (host), abscisic acid (ABA)-deficient tomato mutant Sitiens and its wild-type Rheinlands Ruhm (Rhe) plants under cadmium (Cd) stress. A 100-μM Cd application to host, Sitiens and Rhe reduced the shoot growth, chlorophyll content and stomatal conductance. However, these parameters were significantly (P?<?0.0011) higher (1.0- to 2.6-folds) in host, Sitiens and Rhe under endophytic association than in non-endophyte infected plants (control) under Cd stress. Furthermore, endophytic association minimized the Cd-induced membrane injury and oxidative stress to host, Sitiens and Rhe plants by reducing electrolytes and lipid peroxidation while increasing the content of reduced glutathione and catalase activities as compared to non-endophyte-infected plants. Stress-responsive ABA content significantly increased (~2-folds) in Sitiens and Rhe under endophyte association, while in host plants it was decreased under Cd stress. Salicylic acid content was ~?1.7-fold higher in host, Sitiens and Rhe plants under Cd stress and endophyte association than in the control. Besides gibberellins production, the endophyte has the potential to solubilize phosphates (12.73?±?0.24 mg/l) since higher P was observed in the roots of Sitiens, Rhe and host plants. Similarly, nutrients like sulfur and calcium were more efficiently assimilated in roots of endophyte-associated plants than control under Cd stress. Conversely, Cd accumulation was significantly decreased (P?<?0.001) in the roots of endophyte-inoculated host, Sitiens and Rhe than control. In conclusion, endophyte symbiosis can counteract heavy metal stress which can exert negative effects on plant growth. 相似文献
195.
The state of urban seedling nurseries in the north-eastern region of Bangladesh is examined with a focus on production and profitability of the enterprises. Twenty-eight sample nurseries out of the 97 nursery enterprises in Sylhet town were selected at random, and operators personally interviewed. It was found that the entrepreneurs are not highly educated though they believed that a basic level of education is required to understand the management of young nursery stock. Labourers of various employment categories work in the enterprises and their wage is determined by their skill, gender and efficiency. Capital and operating costs vary among the enterprises according to land value, production capacity, infrastructure type and workforce size. Production capacity ranges from 10,000 to 5 M seedlings/year with an average 836,000, though actual average production is only 341,000 seedlings/year. The production cost per seedling ranges from Tk. 4 to 50 while sale value ranges from Tk. 10 to 60. The most frequently sold species are Acacia mangium, Swietenia macrophylla, Tectona grandis, Mangifera indica, Litchi chinensis and Cocos nucifera. Nursery techniques and cultural practices adopted by nursery operators depend on the type of species and its silvicultural requirement. Despite some problems, including lack of suitable land for nursery establishment and inadequate level of technical knowledge for high quality seedling management, it seems that production of tree seedlings is a promising profitable small-scale business in the study area. 相似文献
196.
孟加拉无机肥料对几种农林作物生物固氮和种苗生长的影响(英文) 总被引:1,自引:0,他引:1
Mohammad Belal Uddin Mohammed Abu Sayed Arfin Khan Sharif Ahmed Mukul Mohammed Kamal Hossain 《林业研究》2008,19(4):303-306
比较了不同浓度无机肥料(尿素和重过磷酸钙)对四种农林作物(楹树、雨豆树、相思树和印度田菁)生物固氮和种苗生长的影响。种子萌发一个月后利用不同浓度肥料(尿素:40kg·hm-2,80kg·hm-2;重过磷酸钙:40kg·hm-2,80kg·hm-2;(尿素 重过磷酸钙)40kg·hm-2和(尿素 重过磷酸钙)80kg·hm-2)处理种苗。结果表明:中等浓度无机肥料促进了种苗的生长,但较高浓度无机肥料也不利于种苗的生长。当施加尿素时根瘤菌的数量大小明显受抑制,但随着增加磷肥(重过磷酸钙)根瘤菌的数量大小增加。本研究有助于农业人员利用无机肥料改善土壤提高农林作物的生物固氮和种苗生长。图2表6参33。 相似文献
197.
Chemical analysis of an M1 agar plate cultivation of a marine fish-gut-derived fungus, Chrysosporium sp. CMB-F214, revealed the known chrysosporazines A–D (11–14) in addition to a suite of very minor aza analogues 1–6. A microbioreactor (MATRIX) cultivation profiling analysis failed to deliver cultivation conditions that significantly improved the yields of 1–6; however, it did reveal that M2 agar cultivation produced the new natural product 15. A precursor-directed biosynthesis strategy adopting supplementation of a CMB-F214 M1 solid agar culture with sodium nicotinate enhanced production of otherwise inaccessible azachrysposorazines A1 (1), A2 (2), B1 (3), C1 (4), C2 (5) and D1 (6), in addition to four new chrysosporazines; chrysosporazines N–P (7–9) and spirochrysosporazine A (10). Structures inclusive of absolute configurations were assigned to 1–15 based on detailed spectroscopic and chemical analyses, and biosynthetic considerations. Non-cytotoxic to human carcinoma cells, azachrysosporazies 1–5 were capable of reversing doxorubicin resistance in P-glycoprotein (P-gp)-overexpressing human colon carcinoma cells (SW620 Ad300), with optimum activity exhibited by the C-2′ substituted analogues 3–5. 相似文献
198.
BACKGROUND: Spodoptera litura (F.) is an important pest worldwide, with over 112 host plants, and is exposed to insecticides throughout the year, resulting in the rapid development of resistance. Insecticide mixtures can delay the development of resistance more effectively than sequences or rotations. Cypermethrin, deltamethrin, profenofos, chlorpyrifos and fipronil were assessed separately and in mixtures against laboratory susceptible S. litura and two field‐collected populations. RESULTS: The field‐collected population from Khanewal (KWL) was significantly more resistant to cypermethrin, deltamethrin, chlorpyrifos and profenofos than one collected from Muzaffar Garh (MGH). Mixtures of cypermethrin + chlorpyrifos or profenofos and of deltamethrin + chlorpyrifos or profenofos at 1:1, 1:10 and 1:20 ratios significantly increased (P < 0.01) toxicity to cypermethrin and deltamethrin in field populations. The combination indices of cypermethrin + chlorpyrifos at 1:1 and 1:10 ratios and cypermethrin + fipronil at 1:1, 1:10 and 1:20 ratios for the KWL strain and of cypermethrin + profenofos or fipronil at 1:1, 1:10 and 1:20 ratios for MGH were significantly below 1, suggesting synergistic interactions. The inhibitors DEF and PBO largely overcame resistance to deltamethrin, cypermethrin and profenofos, suggesting that resistance to the insecticides was associated with esterase and monooxygenase detoxification respectively. CONCLUSION: Chlorpyrifos, profenofos and fipronil could be used in mixtures to restore cypermethrin and deltamethrin susceptibility. These findings may have considerable practical implications for S. litura resistance management. Copyright © 2008 Society of Chemical Industry 相似文献
199.
The ethanol extract of leaves of Derris uliginosa given by oral route at dose of 250 and 500 mg/kg produced a significant inhibition on acetic acid-induced writhing in mice. 相似文献
200.
对孟加拉吉大港地区家庭竹子手工业非农就业的潜力以及对其产生的社会经济效益进行了调查。本地区有40个竹企业,涉及到Hathazcori upazila的4个村庄。80%手工业者的年龄在30~50岁。他们的大多数是未受教育和土地贫瘠的家庭成员。50%的企业是由夫妻或3~5个工人组成的。竹产品主要是满足当地市场的需求。产品是根据季节的变化而决定的。5个产品中,竹书架提供了企业月净收入的41%,平均月净利润约2373.48塔卡,这为促进乡村经济发展起到重要的作用。作者对竹产业发展的状况进行了验证,并提出了建议。 相似文献