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1.
Populations of carrot (Daucus carota) were raised over a widerange of densities (795763 plants m-2) to examine thedynamics of competition in terms of yielddensity relationshipsand size variability, and to investigate the effects of nutrientsupply on competition. While the relationship between shootyield and density was asymptotic, the relationship between rootand total yield and density tended to be parabolic. For a giventime and density series the relationship between yield per unitarea and density could best be described by the model: y=wmD(1+aD)b wherey is the yield per unit area,D is density,wm, a andb arefitted parameters. The parameterswm anda increased over timebut nutrient availability affected onlywm. An extension of thebasic yield-density model is proposed to describe the dynamicsof the yielddensity relationship over time: y=kD[1+cexp(-rt)]{1+ 相似文献
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Silan F Gultekin Y Atik S Kilinc D Alan C Yildiz F Uludag A Ozdemir O 《Molecular biology reports》2012,39(2):1595-1599
Prostate cancer is a common malignancy that develops by structural mutation(s) and/or other genetic alterations in specific
genes.The G to T transversions in codon 12 and C to T transitions in codon 13 of KRAS proto-oncogene are predominant point
mutations that occur in about 20% of different cancers in human. In the current study it was aimed to investigate the prevalence
and predictive significance of KRAS mutations in patients with prostate carcinomas. In a total of 30 fresh tumoural tissue
specimens were investigated in patients with prostate carcinoma. All tumoural specimens were histo-pathologically diagnosed
and genotyped for codon 12, 13 KRAS point mutations by reverse hybridisation and direct sequencing methods. KRAS mutations
were found in 12 (40%) samples with 29 samples deriving from adenocarcinomas and 1 sample was small cell prostate carcinoma.
In 1 (3.44%) sample codon 12 was found to be mutated and in 2 (6.8%) samples codon 13 and in 9 (31%) samples combined codon
12 and 13 were found to be mutated particularly in higher grade of tumoural tissues. Our study, based on representative collection
of human prostate tumours, indicates that combined mutations in codons 12 and 13 KRAS are relatively infrequent and most commonly
occur in prostate carcinomas. 相似文献
3.
QIAN‐WAN MENG YI‐BO LUO 《Botanical journal of the Linnean Society. Linnean Society of London》2008,158(4):689-695
A new species, Galearis huanglongensis Q.W.Meng & Y.B.Luo, is described and illustrated. It is similar to Galearis cyclochila (Franch. & Sav.) Soó and Galearis diantha (Schltr.) P.F.Hunt, but differs in having a short spur, two elliptical lateral stigma lobes and distinctly separated bursicles. This new species is known only from the type locality, the Huanglong Valley, Songpan County, western Sichuan, China, growing amongst mosses under alpine shrubs at an elevation of about 3000 m. Based on two years of observations of its population size, the species was categorized as critically endangered CR (B1a, B2a) according to the World Conservation Union (IUCN) Red List Categories and Criteria, Version 3.1. The micromorphology of pollinia and seeds was observed by scanning electron microscopy and compared with that of G. cyclochila and G. diantha. The results supported G. huanglongensis Q.W.Meng & Y.B.Luo as a new species. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 689–695. 相似文献
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The rapid development of genomic technology has made high throughput genotyping widely accessible but the associated high throughput phenotyping is now the major limiting factor in genetic analysis of traits. This paper evaluates the use of thermal imaging for the high throughput field phenotyping of Solanum tuberosum for differences in stomatal behaviour. A large multi-replicated trial of a potato mapping population was used to investigate the consistency in genotypic rankings across different trials and across measurements made at different times of day and on different days. The results confirmed a high degree of consistency between the genotypic rankings based on relative canopy temperature on different occasions. Genotype discrimination was enhanced both through normalising data by expressing genotype temperatures as differences from image means and through the enhanced replication obtained by using overlapping images. A Monte Carlo simulation approach was used to confirm the magnitude of genotypic differences that it is possible to discriminate. The results showed a clear negative association between canopy temperature and final tuber yield for this population, when grown under ample moisture supply. We have therefore established infrared thermography as an easy, rapid and non-destructive screening method for evaluating large population trials for genetic analysis. We also envisage this approach as having great potential for evaluating plant response to stress under field conditions. 相似文献
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