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991.
在泰国热带季风气候条件下,G156S于3月下旬抽穗,其育性表现为全不育,主茎叶片数14叶.但其播始历期比在贵阳生态条件下主茎叶片数同为14叶时缩短了20d,而其他农艺性状表现变化不大.人工气候葙鉴定结果显示,参试单株其育性发生了漂变,不育临界起点温度比原来提高了0.5℃. 相似文献
992.
In maize, the effects of nitrogen (N) deficiencies on the determination of kernel number per plant (KNP) have been described only by changes in plant growth rate during the critical period for kernel set (PGRcp). We hypothesize that N availability affects KNP also through variations in biomass allocation to the ear, which determines a stable N concentration in this organ. Six maize hybrids of different breeding origin were evaluated in field experiments at two N levels (0 and 400 kg N ha−1 applied). Traits included were KNP and per apical ear (KNE1), and the allometric estimation of PGRcp, ear growth rate during the critical period (EGRcp), and N content and N concentration in different plant organs. We demonstrated that (i) N availability promoted differences among genotypes (G) in the response of EGRcp and KNP to PGRcp, (ii) variations in KNE1 were explained by EGRcp (r2 = 0.64) and by ear N content at silking + 12 d (r2 = 0.64), and (iii) ear N concentration was a highly conservative trait (range between 10.47 and 15.98 mg N g biomass−1) as compared to N concentration in vegetative tissues (range between 4.94 and 18.04 mg N g biomass−1). Three response patterns were detected among hybrids, one for which the relationship between EGRcp and PGRcp did not vary between N levels and experiments, a second one for which N availability affected this relationship, and a third one for which the response was affected by the year (Y) effect. These results, together with the high correlation between EGRcp and ear N content (r2 = 0.88), evidenced the importance of both photo-assimilate and N availability on EGRcp and KNP determination. Values of 1.5–2.3 g ear−1 d−1 during the critical period and 0.49–0.70 g of N ear−1 at silking + 12 d were determined as thresholds for maximizing KNE1, and both could be easily estimated by means of allometric models. 相似文献
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995.
根据Thanatephorus cucumeris G蛋白β亚基序列(AY884129)设计引物,对水稻立枯丝核菌AG 1IA的 G蛋白β亚基基因进行了克隆。PCR结果得到1条约为1.9 kb的扩增片段,包含1个约1.7 kb的完整开放阅读框,编码366个氨基酸。同源性检索发现该序列与大量G蛋白β亚基基因明显同源,一致性介于57.34%~88.14%。根据其推导cDNA序列设计引物进行RT PCR分析,发现该基因在对数生长期表达量最高,提示水稻立枯丝核菌AG 1IA G蛋白β亚基基因可能具有时空表达特性。 相似文献
996.
A complex, polygenic resistance to Plum pox virus (PPV) was previously described in a wild peach-related species, Prunus davidiana clone P1908. In the current study, an analysis of quantitative trait loci (QTL) was performed on an F2 population comprising 99 individuals obtained by selfing the F1 individual #40 of an interspecific cross between susceptible nectarine cv. Summergrand and the resistant P. davidiana clone P1908. Six QTL were identified using both parametric and non-parametric methods of detection, individually explaining 5–28% of the phenotypic variance. The total phenotypic variation explained ranged from 29 to 58%. Alignment of the genetic map of the F2 cross with the P. davidiana parent map showed consistency of QTL over generations, with three of the six QTL co-localizing at the 1-LOD interval and another one at the 2-LOD interval. Two of the QTL were mapped onto linkage group one, where resistance to PPV was previously mapped in apricot. Development and mapping of new microsatellite markers linked to candidate genes revealed a striking co-localization of three of the detected QTL with gene copies coding for eukaryotic translation initiation factors eIF4E and eIF(iso)4G. As co-localization of one QTL with candidate gene eIF(iso)4E was previously reported in the F1 population, the results reported here strongly reinforce the idea that components of the eukaryotic translation initiation complex are correlated with resistance to PPV in P. davidiana P1908. 相似文献
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通过对两套材料(15个海岛棉及其陆海杂种F1与89个陆海杂种BC2F1群体株系)霜后大铃(未正常吐絮)与霜前自然吐絮铃纤维品质性状的分析,结果为除比强度和伸长率外,2003年的15个材料霜后大铃比正常吐絮铃的平均纤维长度短1.15mm、马克隆值降低1.00、整齐度减少2.16,差异都达到了极显著水平;除纤维长度外,2005年的89个群体株系霜后大铃比自然吐絮棉铃平均纤维比强度增加1.73cN/tex、马克隆值降低1.33、整齐度减少0.49、伸长率增加0.21,差异也都达到了极显著水平。霜后大铃与自然吐絮铃纤维品质均存在显著或极显著的正相关,不同材料霜后大铃纤维品质性状的变化趋势与自然吐絮铃的基本一致。这说明了霜后大铃对多数纤维品质性状具有显著的影响,特别是马克隆值和纤维整齐度。但是与自然吐絮棉铃一样,霜后大铃仍能基本反应材料间的纤维品质性状的遗传差异,这对陆海杂种棉花纤维品质遗传研究和育种选择意义重大。 相似文献
999.
新疆小麦黑胚籽粒分离鉴定初报 总被引:3,自引:0,他引:3
对采自南北疆的31个县市119份小麦样品,初步的分离鉴定结果表明:新疆地区小麦黑胚病籽粒的分离物以细链格孢[Alternaria tenuis C. G. Nees]和小麦根腐离蠕孢[Biplaris sorokiniana (Sacc.) Shoem]为主,同时分离到细极链格孢[Alternaria tenuissima (Kunze ex Pers.) Wiltshire]、芽枝霉[Cladosporum spp.]、匍枝霉[Stemphylium spp.]、镰刀菌[Fusarium spp.]、球黑孢霉[Nigrospora sphaerica (Sacc.) Mason],但出现的几率不大.在吐鲁番地区小麦黑胚籽粒中分离到喙状突脐霉(拟)[Exserohilum rostratum (Drech) Leo.& Sug.],在和静的黑胚籽粒中,匍枝霉[Stemphylium spp.]分离率较多,同时分离出小麦生链格孢[Alternaria triticicola Vasant Rao]. 相似文献
1000.
长江上游中华沙鳅遗传多样性研究 总被引:8,自引:4,他引:4
测定了采自3个地理位置(宜宾、江津、思南)共45尾中华沙鳅(Botia superciliaris)的线粒体DNA控制区序列。结果显示:在所有个体913 bp序列中检测到22个变异位点,45尾个体中发现26种单倍型。中华沙鳅的平均核苷酸多样性指数π较低(0.00365),而平均单倍型多样性指数Hd较高(0.986)。中性检验Fu′sFs值为-9.49536(P<0.05)。3个群体内的Kimura 2-paramter遗传距离为0.00329~0.00417,群体间为0.00340~0.00379,群体间和群体内的遗传距离处于同一水平。分子变异分析(AMOVA)结果显示:Fst=0.0291(P<0.01),2.9%的变异来自群体间,97.1%的变异来自群体内;在NJ聚类树中,3个群体的个体并没有按相应的地理位置进行聚类。 相似文献