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21.
AFLP profiles were generated from poplar leaf rust ( Melampsora larici-populina ) collected from Populus trichocarpa cv. Trichobel at six sites in the UK in 2001. Of a total of 145 isolates, 121 were unique AFLP phenotypes. On one occasion, the same AFLP phenotype was found at two sites. The analysis indicated that 81·88% of the total variation was attributable to differences among individuals within replicate plots, 3·47% to differences among plots within sites and 14·65% to differences among sites. Weir & Cockerham's θ was calculated as 0·138 and θ B , the Bayesian analogue of F ST , as 0·146. Overall, there was sufficient gene flow among different sites to prevent genetic drift, as Nm was calculated as 1·562 using θ and as 1·462 using θ B . Nei's genetic distance and population-assignment test indicated that the rust from a site in north-east England was differentiated from those from other sites. There was no significant correlation between genetic and geographical distances. The results indicate that sexual reproduction has a major influence on the relative lack of population structure of M. larici-populina in the UK. 相似文献
22.
《植物养料与土壤学杂志》2017,180(2):178-186
Positive effects of pyrochar on soil nutrient availability and plant growth are widely reported in literature. However, few studies have reported effects of hydrochars on plant nutrition. A pot trial was conducted over a period of 2 years to investigate the effect of a pyrochar (AGT) and a hydrochar (HTC) on poplar (Populus × generosa , clone AF8) growth, biomass allocation and nitrogen (N) uptake with special emphasis on the quantification (using an isotopic mass balance approach) of char‐derived nitrogen (CDN) absorbed by plants. We found that both pyrochar and hydrochar positively affected above‐ground biomass productivity in the first year, and biomass and nitrogen (N) allocation over the 2 years by reducing the allocation of resources to fine roots. By the end of the experiment, even though the total N uptake was not affected by char, the CDN was more than 24% of the total N absorbed by HTC‐treated plants compared to a negligible amount absorbed by AGT‐treated ones. Finally, char did not affect nitrogen use efficiency (NUE) in the first year of growth, but by the end of the experiment, NUE was higher in the above‐ground biomass of HTC‐treated than in AGT‐ and control poplars. 相似文献
23.
The effect of water state of soil on eco-boundary over leaf surface was disscussed by takingPopulus davidiana as experimental material. The results show that to change soil water state by some methods was to adjust and control the
forming quality of eco-boundary in fact. The plant in good water condition must be accompanied by thinner eco-boundary. This
eco-boundary is beneficial to exchange and flow of the substances between plant and environment.
Suifenhe Animal and Plant Quarantine Bureau
The study was supported by The Chinese Natural Science Foundation, No. 39470136
(Responsible Editor: Chai Ruihai) 相似文献
24.
欧美杨优良无性系选择 总被引:1,自引:0,他引:1
经过5年欧美杨优良无性系选育研究,综合生长性状及独立淘汰法,初步选择出适于吉林省中东部河流冲积平地和四旁绿化造林的欧美杨优良无性系为N2、N12。平均单株材积分别是对照的414.9%和398.5%;最大单株树高、胸径分别为7.80m和7.6cm,在造林地表现出明显的生长优势。 相似文献
25.
Genome-wide search for segregation distortion loci associated with the expression of complex traits in Populus tomentosa 总被引:1,自引:0,他引:1
Segregation distortion of molecular markers has been reported in a broad range of organisms. It has been detected in an interspecific BC1 Populus pedigree established by controlled crossing between clone “LM50” (Populus tomentosa) and its hybrid clone “TB01” (P. tomentosa×P. bolleana). The study with a total of 150 AFLP markers (approximately 18.9% of the total loci) exhibited significant deviation from the Mendelian ratio (1:1) (p<0.01). Twenty-five percent of the markers were mapped on the pa-rental specific genetic linkage maps of clones “LM50” and “TB01” with a pseudo-test-cross mapping strategy. Twelve linkage groups had markers with skewed segregation ratios, but the major regions were on linkage groups TLG2, TLG4 and TLG6 in the linkage map of clone “LM50”. We also analyzed the association between distorted loci and expression of complex traits with Map-maker/QTL software. A total of 16 putative QTLs affecting 12 traits were identified in the distorted regions on seven linkage groups. Therefore we could detect the distribution of skewed loci along the entire genome and identify the association between quantitative traits and segregation loci via genetic mapping in an interspecific BC1 P. tomentosa family. Furthermore, the genetic nature and pos-sible causes of these segregation distortions for differentiation between female and male parents were also discussed. 相似文献
26.
杨树伐根嫁接毛白杨试验研究 总被引:2,自引:0,他引:2
试验结果表明:不同的白杨派品种对嫁接亲合力的敏感程度不同,敏感性最强的是白杨的741,敏感性最低的是河北毛白杨;选用生长健壮的种条作接穗,伐根生长旺盛,直径在10cm以上,嫁接时间掌握在4月份,且边平茬边嫁接是提高嫁接成活率的主要措施; 相似文献
27.
大青杨无性系育苗及造林技术 总被引:1,自引:0,他引:1
阐述大青杨优良无性系苗木繁育及栽培技术。苗木培育以扦插育苗为主,育苗地应选择地势较为平坦,排水良好,具有灌溉条件,土壤比较肥沃疏松的壤土或沙壤土为好;种条采集应在晚秋至早春苗木休眠期内进行,最好采用一年生平茬苗干,选无病虫害、生长健壮、水份充足、冬芽饱满的枝条做种条,插穗的长度12~15 cm为宜。扦插时间一般当天最高气温大于16℃时即可进行。可采取高床或垄式扦插,扦插时最好覆膜。造林时采用"根苗"造林。幼林抚育根据造林《规程》采取3、2、2、1次抚育。造林后结合头2次幼林抚育及时定干,每株保留1个健壮的萌条,否则影响生长。 相似文献
28.
柴达木地区新疆杨扦插育苗试验 总被引:1,自引:0,他引:1
通过新疆杨插穗催根不同处理方法和扦插时间对比试验,总结出柴达木地区新疆杨扦插育苗过程中最佳的插穗催根方法和扦插时间。 相似文献
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