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91.
How the power required for bird flight varies as a function of forward speed can be used to predict the flight style and behavioral
strategy of a bird for feeding and migration. A U-shaped curve was observed between the power and flight velocity in many
birds, which is consistent to the theoretical prediction by aerodynamic models. In this article, we present a general genetic
model for fine mapping of quantitative trait loci (QTL) responsible for power curves in a sample of birds drawn from a natural
population. This model is developed within the maximum likelihood context, implemented with the EM algorithm for estimating
the population genetic parameters of QTL and the simplex algorithm for estimating the QTL genotype-specific parameters of
power curves. Using Monte Carlo simulation derived from empirical observations of power curves in the European starling (Sturnus vulgaris), we demonstrate how the underlying QTL for power curves can be detected from molecular markers and how the QTL detected
affect the most appropriate flight speeds used to design an optimal migration strategy. The results from our model can be
directly integrated into a conceptual framework for understanding flight origin and evolution. 相似文献
92.
Clustering among loci underlying soybean resistance to Fusarium solani, SDS and SCN in near-isogenic lines 总被引:3,自引:0,他引:3
K. Meksem T. W. Doubler K. Chancharoenchai N. Nijti S. J. Chang A.P. Rao Arelli P. E. Cregan L. E. Gray P. T. Gibson D. A. Lightfoot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(7-8):1131-1142
In the soybean [Glycine max (L.) Merr.] cultivar ’Forrest’ a single chromosomal region underlies co-inheritance of field resistance of the sudden-death
syndrome (SDS), caused by the fungus Fusarium solani (Mart.) Sacc. f. sp. glycines (Burk.) Snyd. & Hans. and soybean cyst nematode (SCN) race 3 (caused by Heterodera glycines Ichinohe). Our objectives were to verify that co-inheritance was derived from a single chromosomal region in near-isogenic
lines and to separate component gene clusters. DNA markers were compared with a SDS leaf-scorch index (DX), F. solani root-infection severity (IS) and a SCN index of parasitism (IP) among 80 near-isogenic lines (NILs). The genomic region identified
by the RFLP marker Bng122D was strongly associated (0.0004 ≤P≤ 0.006) with mean SDS DX (R
2 > 16–38%) and IS (R
2 > 38–73%), but only marginally associated with resistance to SCN. However, the linked (4.3–7.4 cM) microsatellite marker
SATT309 was strongly associated with both resistance to SCN (0.0001 ≤P≤ 0.0003; R
2 > 24–97%) and mean leaf DX (0.0001 ≤P≤ 0.0003; R
2 > 25–63%), but not root IS. Recombination events among markers and traits enabled separation of the qualitative loci underlying
resistance to SDS and SCN. Our data showed that resistance to SDS DX, SDS IS and SCN IP in Forrest may be caused by four genes
in a cluster with two pairs in close linkage or by a two-gene cluster with each gene displaying pleiotropy, one conditioning
SDS IS and DX and the other SCN IP and SDS DX.
Received: 22 September 1998 / Accepted: 12 May 1999 相似文献
93.
利用重组自交系和SSR标记进行陆地棉株型QTL的鉴定和定位 总被引:6,自引:1,他引:6
通过中棉所12与8891的杂交及多代自交,获得由180个家系构成的重组自交系F8、F9群体。重组自交系群体、两亲本及F1于2002、2003两年种植;对株型性状进行了研究,两年共调查了10个株型形状。利用该重组自交系群体,采用SSR为主体的分子标记构建了遗传连锁图,并对株型性状进行了单位点和双位点水平的QTL定位。结果表明,QTL加性效应和上位性互作效应作为棉花重组自交系株型性状的遗传基础起着重要作用;中棉所12与8891间多态性位点偏少,而表型差异较大且其杂交种湘杂棉二号有很强的杂种优势,QTL互作可部分解释这一现象:结合对产量品质性状的研究结果,认为上位性可能是湘杂棉二号杂种优势的重要遗传基础。 相似文献
94.
95.
Kimberley B. Ritter David R. Jordan Scott C. Chapman Ian D. Godwin Emma S. Mace C. Lynne McIntyre 《Molecular breeding : new strategies in plant improvement》2008,22(3):367-384
QTL for stem sugar-related and other agronomic traits were identified in a converted sweet (R9188) × grain (R9403463-2-1)
sorghum population. QTL analyses were conducted using phenotypic data for 11 traits measured in two field experiments and
a genetic map comprising 228 SSR and AFLP markers grouped into 16 linkage groups, of which 11 could be assigned to the 10
sorghum chromosomes (SBI-01 to SBI-10). QTL were identified for all traits and were generally co-located to five locations
(SBI-01, SBI-03, SBI-05, SBI-06 and SBI-10). QTL alleles from R9188 were detected for increased sucrose content and sugar
content on SBI-01, SBI-05 and SBI-06. R9188 also contributed QTL alleles for increased Brix on SBI-05 and SBI-06, and increased
sugar content on SBI-03. QTL alleles from R9403463-2-1 were found for increased sucrose content and sucrose yield on SBI-10,
and increased glucose content on SBI-07. QTL alleles for increased height, later flowering and greater total dry matter yield
were located on SBI-01 of R9403463-2-1, and SBI-06 of R9188. QTL alleles for increased grain yield from both R9403463-2-1
and R9188 were found on SBI-03. As an increase in stem sugars is an important objective in sweet sorghum breeding, the QTL
identified in this study could be further investigated for use in marker-assisted selection of sweet sorghum. 相似文献
96.
多基因抗性的QTL作图及其在作物持久性抗病育种上的应用 总被引:3,自引:1,他引:3
QTL作图已成为解析生物复杂性状遗传基础和基因座之间互作机制的一种有效的研究工具。多基因抗性没有明显的生理小种特异性,一般表现为数量性状。多基因抗性的QTL作图在植物持久性抗病育种中有重要的应用价值,有助于分离到广谱性抗病基因。从作图群体(F1、F2、DH、RIL、BIL和NIL)构建、抗性表型测定和标记辅助育种等方面论述了多基因抗性QTL作图的最新研究进展。 相似文献
97.
98.
Identification of QTL for growth- and grain yield-related traits in rice across nine locations of Asia 总被引:19,自引:0,他引:19
Hittalmani S Huang N Courtois B Venuprasad R Shashidhar HE Zhuang JY Zheng KL Liu GF Wang GC Sidhu JS Srivantaneeyakul S Singh VP Bagali PG Prasanna HC McLaren G Khush GS 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(4):679-690
Rice double-haploid (DH) lines of an indica and japonica cross were grown at nine different locations across four countries in Asia. Genotype-by-environment (G x E) interaction analysis for 11 growth- and grain yield-related traits in nine locations was estimated by AMMI analysis. Maximum G x E interaction was exhibited for fertility percentage number of spikelets and grain yield. Plant height was least affected by environment, and the AMMI model explained a total of 76.2% of the interaction effect. Mean environment was computed by averaging the nine environments and subsequently analyzed with other environments to map quantitative trait loci (QTL). QTL controlling the 11 traits were detected by interval analysis using mapmaker/qtl. A threshold LOD of >/=3.20 was used to identify significant QTL. A total of 126 QTL were identified for the 11 traits across nine locations. Thirty-four QTL common in more than one environment were identified on ten chromosomes. A maximum of 44 QTL were detected for panicle length, and the maximum number of common QTL were detected for days to heading detected. A single locus for plant height (RZ730-RG810) had QTL common in all ten environments, confirming AMMI results that QTL for plant height were affected the least by environment, indicating the stability of the trait. Two QTL were detected for grain yield and 19 for thousand-grain weight in all DH lines. The number of QTL per trait per location ranged from zero to four. Clustering of the QTL for different traits at the same marker intervals was observed for plant height, panicle number, panicle length and spikelet number suggesting that pleiotropism and or tight linkage of different traits could be the possible reason for the congruence of several QTL. The many QTL detected by the same marker interval across environments indicate that QTL for most traits are stable and not essentially affected by environmental factors. 相似文献
99.
许多研究认为,在一定范围内,叶绿素含量与光合速率成正相关关系、叶绿素含量高的水稻叶片能延缓衰老。理论上推算,水稻叶片如果推迟1天衰老,可使水稻增产2%左右,而实际实验结果表明可增产1%左右。叶片早衰往往也是造成有些水稻品种结实率偏低、空秕率较高及产量降低的主要原因。叶片衰老是水稻发育过程中的生命现象,它是水稻在长期进化过程中形成的适应性。叶片衰老的显著特征之一是叶绿素含量下降,叶色褪绿变黄。[第一段] 相似文献
100.
A. A. Gheyas R. D. Houston J. C. Mota-Velasco D. R. Guy A. E. Tinch C. S. Haley J. A. Woolliams 《Animal genetics》2010,41(5):531-536
In a previous study, three significant quantitative trait loci (QTL) associated with resistance to Infectious Pancreatic Necrosis (IPN) disease were identified by analysing challenge data from one sub-population of Landcatch Atlantic salmon (Salmo salar) smolt. While these QTL were shown to affect the resistance in seawater, their effect in freshwater was unknown. This study investigates the effect of these QTL on IPN resistance in salmon fry in freshwater. Twenty families with intermediate levels of IPN mortality were analysed from a freshwater challenge trial undertaken on a different sup-population of LNS salmon to that studied previously. Only the QTL from linkage group 21 (LG21) appeared to have a significant and large effect on resistance in freshwater; the same QTL was found to have the largest effect in seawater in the previous study. Variance component analysis showed a high heritability for the QTL: 0.45 ± 0.07 on the liability scale and 0.25 ± 0.05 on the observed scale. In a family where both parents were segregating for the QTL, there was a 0% vs. 100% mortality in homozygous offspring for resistant and susceptible QTL alleles. The finding that the same QTL has major effect in both freshwater and seawater has important practical implications, as this will allow the improvement of resistance in both phases through marker assisted selection by targeting this QTL. Moreover, the segregation of the LG21 QTL in a different sub-population gives further evidence of its association with IPN-resistance. 相似文献