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51.
CYTOKININ PRODUCTION BY ECTOMYCORRHIZAL FUNGI 总被引:1,自引:1,他引:0
52.
Foliar blight and dieback of durian seedlings and trees in Peninsular Malaysia was found to be caused by Rhizoctonia solani (teleomorph - Thanatephoms cucumeris) The fungus grew well and produced abundant sclerotia at temperatures higher than 24°C with an optimum at 28°C. It grew poorly at 35°C and did not grow at 10°C. The strains studied were found to belong to the anastomosis group AG-1. They were pathogenic on durian, papaya, cucumber, long bean, Mikania weed, padi, musk melon, mung bean, Zoysia grass, Bermuda grass, and St Augustine grass. They were mildly pathogenic on groundnut, and non-pathogenic on maize, guava and Brassica‘pak choy’. The disease was effectively controlled by foliar sprays of pencycuron and benomyl; triadimefon and an antagonistic bacterium suspension treatment were less effective and quintozene-etridiazole mixture gave poor disease control. 相似文献
53.
The incorporation of proteins into microparticles fabricated by layer-by-layer adsorption of oppositely charged polyelectrolytes (dextran sulfate and protamine) on protein microaggregates was studied. Microaggregates with insulin were prepared by two different techniques: 1) formation of insoluble polyelectrolyte complex consisting of insulin and dextran sulfate (aggregate size of 7-20 micro m), or 2) salting out of insulin from solution by sodium chloride (aggregate size of 5-13 micro m). Microparticles varying in the number of cycles (from 1 to 8) of polyelectrolyte adsorption on protein aggregates were examined and compared. Morphology of the microparticles was studied by scanning electron and optical microscopy. It was shown that polyelectrolyte microparticles retained the shape and dimensions of the initial protein aggregates used as a template. Ultrasonication of microparticles obtained using salted out protein aggregates resulted in the formation of stable nanoparticles (100-200 nm). Regulation of protein release from the microparticles of both types by varying the number of polyelectrolyte adsorption cycles and pH of the medium was demonstrated. Insulin not bound to polyelectrolytes was released from the microparticles at pH values between 6 and 8, which corresponds to the pH of the human small intestine and ileum. 相似文献
54.
- Studies have been made of the growth in culture medium of thecomponent parts of compositesegments excised from 3 to 7-day-oldAvena sativa seedlings and comprising portions of coleoptileand first leaf bases and various lengths of first internodetissue.
- The effects of various concentrations of gibberellicacid (GA)and indole-3- acetic acid (IAA) alone and in combinationhavebeen studied on the growth of these organs.
- Both GA andIAA stimulate the growth of coleoptile base tissuebut in combinationtheir joint effects are less than additive.No synergism occurs.
- The growth of the first-leaf base is greatly stimulated byGAbut is inhibited by IAA. In combination, the stimulatoryeffectof GA (up to 1 0 p.p.m.) may be virtually eliminatedby evenlow concentrations of IAA (0.01 p.p.m.).
- The inclusionof first internode tissue in the segments considerablyincreasesthe growth of first leaf base tissue but has no consistenteffecton the growth of coleoptile base tissue. The presenceof firstinternode tissue also greatly increases the degreeof growthstimulation invoked by GA but does not influence thedegreeof IAA inhibition. It is postulated that the first internodetissue is the source of an unknown growth factor necessary forGA action in the first leaf and potentiating the action of endogenousgibberellin.
- Kinetin, adenine sulphate, glutarnine, glutarnicacid, asparagine,glycine, arginine, histidine, lysine, aneurin,and pyridoxinewill not simulate the effects of this unknowngrowth factorin the growth of leaf tissue. Like IAA, kinetinvirtually eliminatesthe GA stimulation of leaf growth.
- Astudy of extracts of internode tissue in various solvents,analysedby paper partition chromatography and assayed by thegrowthof the first leaf base, has indicated the presence ofgrowthinhibitors and gibberellin-like substances but has failedtoisolate the postulated endogenous GA-synergist.
- The implicationsof these results for growth correlations andthe hormone controlof shoot growth in Avena sativa seedlingsis discussed.
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Exposing muskmelon (Cucumis melo L.) cultivar seedlots to N2atmosphere created totally anaerobic conditions which stimulatedethanol production and accumulation in both high and low vigourseeds. However, accumulation of ethanol was consistently higherin the low vigour seeds than in the high vigour ones. In addition,CO2 production under N2 and in air suggests the presence ofan apparent Pasteur effect in the low vigour seedsbut not in the high vigour seeds. Acetaldehyde production underN2 was very low and did not seem to be associated with seedvigour, probably because of its nature as an intermediate inethanol production. The fast shift toward ethanol may be dueto the fact that alcohol dehydrogenase, the enzyme which catalyzesthe conversion of acetaldehyde to ethanol, exists in sufficientamounts in the imbibing seeds so that it is not a limiting factorin the conversion to ethanol. Alcohol dehydrogenase activitydid not appear to be related to seed vigour. Key words: Cucumis melo L., Anaerobic respiration, Germination, Seeds. 相似文献
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Franc-Christophe Baurens Stéphanie Bocs Mathieu Rouard Takashi Matsumoto Robert NG Miller Marguerite Rodier-Goud Didier MBéguié-A-MBéguié Nabila Yahiaoui 《BMC plant biology》2010,10(1):149
Background
Comparative sequence analysis of complex loci such as resistance gene analog clusters allows estimating the degree of sequence conservation and mechanisms of divergence at the intraspecies level. In banana (Musa sp.), two diploid wild species Musa acuminata (A genome) and Musa balbisiana (B genome) contribute to the polyploid genome of many cultivars. The M. balbisiana species is associated with vigour and tolerance to pests and disease and little is known on the genome structure and haplotype diversity within this species. Here, we compare two genomic sequences of 253 and 223 kb corresponding to two haplotypes of the RGA08 resistance gene analog locus in M. balbisiana "Pisang Klutuk Wulung" (PKW). 相似文献60.
Yu Yao Aden Ka-Yin Chan Zhi Yong Qin Ling Chao Chen Xin Zhang Jesse Chung-Sean Pang Hiu Ming Li Yin Wang Ying Mao Ho-Keung NG Liang Fu Zhou 《PloS one》2013,8(6)
Recurrence and progression to higher grade lesions are characteristic behaviorsof gliomas. Though IDH1 mutation frequently occurs and is considered as an early event in gliomagenesis, little is known about its role in the recurrence and progression of gliomas. We therefore analysed IDH1 and IDH2 statusat codon 132 of IDH1 and codon 172 of IDH2 by direct sequencing and anti-IDH1-R132H immunohistochemistry in 53 paired samples and their recurrences, including 29 low- grade gliomas, 16 anaplastic gliomas and 8 Glioblastomas. IDH1/IDH2 mutation was detected in 32 primarytumors, with 25 low- grade gliomas and 6 anaplastic gliomas harboring IDH1 mutation and 1 low- grade glioma harboring IDH2 mutation. All of the paired tumors showed consistent IDH1 and IDH2 status. Patients were analyzed according to IDH1 status and tumor-related factors. Malignant progression at recurrence was noted in 22 gliomas and was not associated with IDH1 mutation. Survival analysis revealed patients with IDH1 mutated gliomas had a significantly longer progression-free survival (PFS) and overall survival (OS). In conclusion, this study demonstrated a strong tendency of IDH1/IDH2 status being consistent during progression of glioma. IDH1 mutation was not a predictive marker for malignant progression and it was a potential prognostic marker for gliomas of Chinese patients. 相似文献