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131.
Zhi-Juan Ji Xiao-Guang Wang Yu-Xiang Zeng Liang-Yong Ma Xi-Ming Li Bing-Xin Liu Chang-Deng Yang 《Breeding Science》2012,62(1):71-77
Five physiological and eleven yield traits of two pairs of sister lines generated from a high generation with similar genetic background (SLs) for purple pericarp were investigated to explore the reasons behind low-yield production of colored rice. Of the five physiological traits examined, except grain anthocyanin content, there were generally similar trends between the P (purple-pericarp) lines and the corresponding W (white-pericarp) lines over two seasons (in the year 2009 and 2010 separately). The results demonstrated that the chlorophyll content of flag leaves, the net photosynthetic rate of flag leaves, and the grain anthocyanin content could be easily influenced by the environment. The physiological functions of the traits for the P lines were more active than those of the corresponding W lines in the year 2010. The grain anthocyanin content of the P lines was much greater in the year 2010 than in the year 2009 during the growth period. The investigation of yield traits revealed that the P lines had reduced 1000-grain weight, yield per plot and grain/brown rice thickness compared to the W lines. A difference comparison of these traits and a source-sink and transportation relationship analysis for these SLs suggested that small sink size was a key reason behind yield reduction of purple pericarp rice. 相似文献
132.
对贵州省大方县1996 ~2012年采集的134只四川短尾鼩体重进行统计分析,结果表明:四川短尾鼩体重最低为12.20 g,最高达48.00 g,平均体重为(31.12±6.48)g,其雌、雄个体体重分布均呈常态分布,个体体重主要分布在22.1 ~40.0 g之间,占总兽类数的85.07%,是活动能力较强的个体.四川短尾鼩达到性成熟的体重界线为22.0 g,怀孕个体最低体重为26.00 g,睾丸下降个体最低体重为23.80 g,随着个体的增长,体重的增加,种群繁殖力不断增强,体重达30.0 g以上时,种群繁殖力迅速增加,平均怀孕率、睾丸下降率和繁殖指数分别为43.75%、80.95%和1.53,说明体重达30.0 g以上个体大部分已达到性成熟,是参与繁殖的主要个体. 相似文献
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134.
回顾森林收获计测技术的发展历史,分析现代电子称量技术的发展应用前景,指出木材及木制品以体积计量计价的局限性和以重量计量计价的优势,认为当前一些木材市场上出现的买卖双方以重量而不是以材积计量计价现象有其历史必然性。基于以重量计量计价更为客观、准确、快捷、高效,并大幅降低成本的优势,其在纸浆等工业原料林经营、林业碳汇贸易等方面具有广泛应用潜力。 相似文献
135.
R. P. Mauro A. Occhipinti A. M. G. Longo G. Mauromicale 《Journal of Agronomy and Crop Science》2011,197(1):57-66
A field‐experiment (2004/2005 and 2005/2006 seasons) was conducted in the coastal plain of south‐eastern Sicily (37°03′N, 15°18′E, 15 m a.s.l.), on a Calcixerollic Xerochrepts soil, aimed at quantifying the effect of shading on chlorophyll (Chl) content, Chl fluorescence, photosynthesis and growth of subterranean clover. Four levels of photosynthetically active radiation reduction (from 0 % to 90 %) were tested on Trifolium brachycalycinum cv. ‘Clare’ and Trifolium subterraneum ecotype ‘Ragalna’. In both species shading progressively increased Fv/Fm, internal CO2 concentration, diffusive leaf resistance and specific leaf area (up to 8 %, 34 %, 18 % and 68 %, respectively), and decreased Chl content, Tmax, photosynthetic rate and plant dry weight (up to 9 %, 24 %, 79 % and 39 %, respectively). As plants aged, characteristic bell‐shaped trends were evident for photosynthetic parameters, with Fv/Fm increasing up until the onset of flowering, and thereafter declining. This implies that Fv/Fm may be a useful indicator of earliness in subterranean clover genotypes. The aboveground dry biomass response to shading was both genotype‐ and season‐dependent, but was predictable from the measurement of relative leaf Chl content. Moreover, our results suggest that an improvement in the interaction between host‐rhizobium may represent a major potential breeding target for enhancing subterranean clover tolerance to shading. 相似文献
136.
《Scandinavian Journal of Forest Research》2012,27(1-4):195-204
A dynamic model of branch length and weight growth was developed for two contrasting sites, both with young stands of spruce. At one site sample trees were obtained from both unfertilised plots and from plots with increased growth rate maintained by annual fertilisation. At the second site unfertilised trees and trees subject to single applications of fertiliser were modelled. A model of the same structure was developed for each site and tested by application at the alternate site. In view of the close agreement between sites, model parameters were calculated based on all data combined. The model is driven by height increment and branch age. The sample trees were mostly open grown so that only a tentative estimate of the effects of between tree competition is given. The limitations of the model are stressed. 相似文献
137.
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139.
王伟 《青海畜牧兽医杂志》2012,42(6):12-13
两个月的试验结果表明,补饲精料对减少牦牛冷季掉膘有明显作用。8月龄牦牛补饲精料试验组比对照组少减重2.81kg,两者之间存在极显著差异(P<0.01)。20月龄补饲精料牦牛试验组比对照组少重2.19kg,两者之间存在极显著差异(P<0.01)。通过计算投产比得出,补饲精料是增加三江源区牦牛冷季营养供给,减少掉膘,提高生产效率的有效途径。 相似文献
140.
通过对极大极小(γ,δ)双子在某一特征值下的等价定义,把任意的极大极小(γ,δ)双子化为极大代数下的双子,从而得到计算极大极小〈γ,δ〉双子M矩阵的特征值与特征向量的方法以及有关的结论。 相似文献