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1.
Heading date and plant height are important determinants for plant growth rate. In this study, simple sequence repeat markers were used to tag quantitative trait loci (QTL) using a recombinant inbred line mapping population derived from two important breeding parents, genetic stock Kaybonnetlpa1-1 and indica cultivar Zhe733, using data collected under field and greenhouse conditions. Interval mapping, composite interval mapping, and multiple interval mapping were performed to map QTL for heading date and plant height, and to identify epistatic interactions between the QTL. qHD3.1 on chromosome 3 from KBNTlpa1-1 had the largest effect on heading date contributing an average of 28.4 % of the total phenotypic variation. qHD7.1, 7.2, and 8.1 also had a significant contribution to heading date from Zhe733 averaging 8.1, 12.8, and 12.8 % of the phenotypic variance, respectively, and there was a positive additive-by-additive epistatic interaction between qHD7.1 and qHD8.1. QTL, qPHT1.1 and qPHT3.1, for plant height were detected on chromosomes 1 and 3, respectively. qPHT1.1 contributed the largest effect representing 38.2 % of the total phenotypic variation. Comparison of the QTL identified in our study with previous results revealed that the chromosomal locations for QTL coincided closely with positions reported previously in other rice populations worldwide, suggesting that these QTL have coevolved and become domesticated. The tightly linked SSR markers that flank these QTL should be desirable for tagging heading date and plant height genes and facilitating their incorporation into advanced breeding lines using marker assisted selection. 相似文献
2.
Baboucarr Manneh Piet Stam Paul C. Struik Samuel Bruce-Oliver Fred A. van Eeuwijk 《Euphytica》2007,156(1-2):213-226
Use of DNA-based markers can accelerate cultivar development in variable cultivation environments since, in contrast to phenotype,
DNA markers are environment-independent. In an effort to elucidate the genetic basis of genotype-by-environment interaction
(G × E) for yield of rice (Oryza sativa L.), the associations between 139 AFLP markers and grain yield were determined for rice grown in fresh water (EC of 0.65 dS m−1) and saline conditions (EC of 4–8 dS m−1) with 0 kg ha−1 or 100 kg ha−1 nitrogen fertilizer in the years 2000 and 2001. A population of recombinant inbred lines of rice, developed from an IR29 × Pokkali
cross, was used in the study. Both genotype × salinity and genotype × nitrogen level interactions were significant, with the
genotype × salinity interaction being stronger. Through multiple regression analysis using a stepwise procedure for selecting
markers, 36 markers were detected for grain yield in the four test conditions and of these 28 were detected in only one test
condition implying strong environmental specificity for yield QTL expression. However, the fact that eight QTLs were detected
in more than one test condition points to the existence of wide-adaptability genes in this cross. Markers with significant
associations with yield explained between 37% and 48% of the yield variation in each test condition. Superior genotypes of
rice were identified in all four test conditions based on their marker signatures. Furthermore, across N fertilizer regimes,
yield predicted from summed additive effects of QTLs were significantly correlated with observed yield in the same year and
across years. Thus marker-assisted selection can help breeders overcome the problem of low selection efficiency encountered
during phenotypic selection for yield in stress environments. 相似文献
3.
Straighthead is a physiological disorder in rice (Oryza sativa L.) resulting in sterile florets, poorly developed panicles and yield loss. Because of its sporadic nature and unidentified causes for the disorder, molecular marker assisted selection is essential for resistance improvement in breeding programmes. To take advantage of recent advances in gene‐mapping technology, we executed a genome‐wide association mapping to identify genetic regions associated with straighthead disorder using 547 accessions of germplasm from the USDA rice core collection. Straighthead was evaluated in arsenic treated soil and genotyping was conducted with 75 molecular markers covering the entire rice genome about every 25 cM. A mixed‐linear model approach combining the principal component assignments with kinship estimates proved to be particularly promising for association mapping. The extent of linkage disequilibrium was described among the markers. Six markers were found to be significantly associated with straighthead, explaining 35% of the total phenotypic variation. However, only two SSR markers, RM413 and RM277 on chromosome 5 and 12, respectively, have a significant association with low rating indicating straighthead resistance. Confirmation of the marker‐straighthead association using segregating populations is necessary before marker‐assisted selection can be applied. 相似文献
4.
Angustias Márquez-Lema José M. Fernández-Martínez Begoña Pérez-Vich Leonardo Velasco 《Euphytica》2008,164(2):365-375
The presence of high levels of sinigrin in the seeds represents a serious constraint for the commercial utilisation of Ethiopian
mustard (Brassica carinata A. Braun) meal. The objective of this research was the introgression of genes for low glucosinolate content from B. juncea into B. carinata. BC1F1 seed from crosses between double zero B. juncea line Heera and B. carinata line N2-142 was produced. Simultaneous selection for B. carinata phenotype and low glucosinolate content was conducted from BC1F2 to BC1F4 plant generations. Forty-three BC1F4 derived lines were selected and subject to a detailed phenotypic and molecular evaluation to identify lines with low glucosinolate
content and genetic proximity to B. carinata. Sixteen phenotypic traits and 80 SSR markers were used. Eight BC1F4 derived lines were very close to N2-142 both at the phenotypic and molecular level. Three of them, with average glucosinolate
contents from 52 to 61 micromoles g−1, compared to 35 micromoles g−1 for Heera and 86 micromoles g−1 for N2-142, were selected and evaluated in two additional environments, resulting in average glucosinolate contents from
43 to 56 micromoles g−1, compared to 29 micromoles g−1 for Heera and 84 micromoles g−1 for N2-142. The best line (BCH-1773), with a glucosinolate profile made up of sinigrin (>95%) and a chromosome number of
2n = 34, was further evaluated in two environments (field and pots in open-air conditions). Average glucosinolate contents over
the four environments included in this research were 42, 31 and 74 micromoles g−1 for BCH-1773, Heera and N2-142, respectively. These are the lowest stable levels of glucosinolates reported so far in B. carinata. 相似文献
5.
Manli Li Nana Yuyama Mariko Hirata Jianguo Han Yunwen Wang Hongwei Cai 《Euphytica》2009,170(3):327-338
A consensus genetic linkage map with 447 SSR markers was constructed for zoysiagrass (Zoysia japonica Steud.), using 86 F1 individuals from the cross ‘Muroran 2’ × ‘Tawarayama Kita 1’. The consensus map identified 22 linkage groups and had a total
length of 2,009.9 cM, with an average map density of 4.8 cM. When compared with a previous AFLP-SSR linkage map, the SSR markers
from each linkage group mapped to similar positions in both maps. Eight pairs of linkage groups from the AFLP-SSR map were
joined into eight new groups in the current map. This zoysiagrass consensus map contained 35 SSR markers exhibiting high homology
with rice genomic sequences from known chromosomal locations. This allowed synteny to be identified between Zoysiagrass linkage
groups 2, 3, 9, 19 and rice chromosomes 3, 12, 2, 7 respectively. These results provide important comparative genomics information
and the new map is now available for quantitative trait locus analysis, marker-assisted selection and breeding for important
traits in zoysiagrass. 相似文献
6.
Rice blast resistance gene ‘Pi-z’ present in rice genotypes, Zenith and Fukunishiki, represents a potential source of blast resistance for the north-western
Himalayan region of India. We tested the reliability of microsatellite markers linked to Pi-z for assessing blast resistance phenotype in crosses of commercial importance. A new set of microsatellite markers linked
to Pi-z was also developed by exploiting the publicly available marker and genomic resources of rice. Of the three previously reported
markers for Pi-z, only MRG5836 was suitable for the marker assisted selection of Pi-z. Among the 17 microsatellites selected from the putative region of Pi-z locus, two, RM8225 and RM8226 cosegregated with MRG5836 and were located at distance of 1.2–4.5 cM from the gene. A new microsatellite marker ‘SSR236’ was developed from the (CT)16 repeat of PAC clone P0502B12, which exhibited closer linkage (0.6–1.2 cM) to Pi-z. Survey of the allelic diversity at the loci of the Pi-z linked microsatellite markers revealed that the Fukunishiki and Zenith type alleles were not present in majority of the local
indica rice genotypes. As these markers are polymorphic between the Pi-z donors and a great majority of local indica rices tested, they can be used as a selection tool in rice breeding programs aimed at improving the blast resistance of local
rices. 相似文献
7.
K. Selvaraju P. Shanmugasundaram S. Mohankumar M. Asaithambi R. Balasaraswathi 《Euphytica》2007,157(1-2):35-43
Rice leaffolder (RLF) (Cnaphalocrocis medinalis (Guenée) is a destructive and widespread insect pest throughout the rice growing regions in Asia. The genetics of resistance
to RLF in rice is very complex and not thoroughly explored. The present study was conducted to detect the quantitative trait
loci (QTL) associated with RLF resistance involving 176 recombinant inbred lines (RILs) of F8 generation derived from a cross between IR36, a leaffolder susceptible variety and TNAULFR831311, a moderately resistant
indica rice culture. Simple sequence repeat (SSR) markers were used to construct specific linkage groups of rice. All the RILs were
screened to assess their level of resistance to RLF by measuring the leaf area damaged. Besides this, the length and width
of the flag leaf of each RIL were measured since these two parameters were considered as correlated traits to the RLF resistance
in rice. All the above parameters observed across the RILs showed quantitative variation. Correlation analysis revealed that
damage score based on greenhouse screening was positively correlated with length and width of the flag leaf. Out of 364 SSR
markers analysed, 90 were polymorphic between the parents. Multi-point analysis carried out on segregating 69 SSR marker loci
linkage group wise resulted in construction of linkage map with eleven groups of 42 SSR markers. Through single marker analysis,
19 SSR markers were found to have putative association with the three phenotypic traits studied. Of these markers, RM472 was
identified as a locus having major effect on RLF resistance trait based on length of the flag leaf. Interval mapping detected
two QTLs on linkage group 1. Among these QTLs, the QTL flanked by RM576–RM3412 were found to be associated with width of the
flag leaf and RLF resistance. The putative SSR markers associated with leaffolder resistance identified in the present study
may be one of the loci contributing resistance to RLF in rice. 相似文献
8.
Ioannis V. Ganopoulos Konstantinos Kazantzis Ioannis Chatzicharisis Irene Karayiannis Athanasios S. Tsaftaris 《Euphytica》2011,181(2):237-251
It is important to couple phenotypic analysis with genetic diversity for germplasm conservation in gene bank collections.
The use of molecular markers supports the study of genetic marker-trait associations of biological and agronomic interest
on diverse genetic material. In this report, 19 Greek traditional sweet cherry cultivars and two international cultivars,
which were used as controls, were grown in Greece and characterized for 17 morpho-physiological traits, 15 simple sequence
repeat (SSR) loci and 10 inter simple sequence repeat (ISSR) markers. To our knowledge, this is the first report on molecular
genetic diversity studies in sweet cherry in Greece. Principal component analysis (PCA) of nine qualitative and eight quantitative
morphological parameters explain over 77.33% of total variability in the first five axes. The SSR markers yielded a combined
matching probability ratio (MPR) of 9.569 × e−12. The 15 SSR loci produced a total of 92 alleles. Ten ISSR primers generated
91 bands, with an average of 9.1 bands per primer. Expected heterozygosity (gene diversity) values of 15 SSR loci and 10 ISSR
markers averaged at 0.683 and 0.369, respectively. Based on stepwise multiple regression analysis (MRA), SSR alleles were
found associated with harvest time and fruit polar diameter. Furthermore, three ISSR markers were correlated with fruit harvest
and soluble solids and four ISSR markers were correlated with fruit skin color. Stepwise MRA identified six SSR alleles associated
with harvest time with a high correlation (P < 0.001), with linear associations with high F values. Hence, data analyzed by the use of MRA could be useful in marker-assisted breeding programs when no other genetic
information is available. 相似文献
9.
B. Tar'an L. Buchwaldt A. Tullu S. Banniza T.D. Warkentin A. Vandenberg 《Euphytica》2003,134(2):223-230
Ascochyta blight caused by the fungus Ascochyta lentis Vassilievsky and anthracnose caused by Colletotrichum truncatum [(Schwein.) Andrus & W.D. Moore] are the most destructive diseases of lentil in Canada. The diseases reduce both seed yield
and seed quality. Previous studies demonstrated that two genes, ral1 and AbR1, confer resistance toA. lentis and a major gene controls the resistance to 95B36 isolate of C. truncatum. Molecular markers linked to each gene have been identified. The current study was conducted to pyramid the two genes for
resistance to ascochyta blight and the gene for resistance to anthracnose into lentil breeding lines. A population (F6:7) consisting of 156 recombinant inbred lines (RILs) was developed from across between ‘CDC Robin’ and a breeding line ‘964a-46’.
The RILs were screened for reaction to two isolates (A1 and 3D2) ofA. lentis and one isolate (95B36) ofC. truncatum. χ2 analysis of disease reactions demonstrated that the observed segregation ratios of resistant versus susceptible fit the two
gene model for resistance to ascochyta blight and a single gene model for resistance to anthracnose. Using markers linked
to ral1 (UBC 2271290), to AbR1(RB18680) and to the major gene for resistance to anthracnose (OPO61250),respectively, we confirmed that 11 RILs retained all the three resistance genes. More than 82% of the lines that had either
or both RB18680 and UBC2271290markers were resistant to 3D2 isolate and had a mean disease score lower than 2.5. By contrast, 80% of the lines that had
none of the RAPD markers were susceptible and had a mean disease score of 5.8. For the case of A1 isolate of A. lentis, more than 74% of the lines that carriedUBC2271290 were resistant, whereas more than 79% of the lines that do not have the marker were susceptible. The analysis of the RILs
usingOPO61250 marker demonstrated that 11out of 72 resistant lines carried the marker, whereas 66 out of 84 susceptible lines had the marker
present. Therefore, selecting materials with both markers for resistance to ascochyta blight and a marker for resistance to
anthracnose can clearly make progress toward resistance in the population.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
Mahipal S. Shekhawat Narpat S. Shekhawat Harish Kheta Ram Mahendra Phulwaria Amit Kumar Gupta 《Journal of Crop Science and Biotechnology》2011,14(2):133-137
An in vitro propagation method for female plants of Momordica dioica (Roxb.) has been established. The nodal segments were harvested and the cut ends of the explants were sealed with wax and
then surface sterilized and cultured. Bud breaking occurred on Murashige and Skoog’s (MS) agar-gelled medium + 2.0 mg L−1 6-Benzylaminopurine (BAP) + 0.1 mg L−1 Indole-3 acetic acid (IAA). The cultures were amplified by passages on MS medium supplemented with 1.0 mg L−1 BAP + 0.1 mg L−1 IAA. Further, shoot amplification (29.2 shoots per vessel) was achieved by subculturing of in vitro regenerated shoot clump on MS medium + 0.5 mg L−1 BAP + 0.1 mg L−1 IAA. The micropropagated shoots were subsequently transferred for root formation on half-strength MS medium + 2.0 mg L−1 Indole-3 butyric acid (IBA) with 89% success rate. The in vitro-regenerated shoots were also rooted ex vitro with 34% success. These plantlets were hardened in the greenhouse and transferred to the field. The established protocol
is suitable for true to type cloning of mature female plant of M. dioica. 相似文献
11.
T. N. Girish T. M. Gireesha M. G. Vaishali B. G. Hanamareddy Shailaja Hittalmani 《Euphytica》2006,152(2):149-161
Genetic variability, correlation, path coefficient analysis and test of normality was conducted in an F8 recombinant inbred aerobic rice population developed by single seed descent method to evaluate its potential as a mapping population. Estimates of genotypic variance, phenotypic variance, genotypic coefficient of variance (GCV), phenotypic coefficient of variance (PCV), heritability in the broad sense (H) and expected genetic advance at 5% selection index (GA) for grain yield and other attributing characters were computed. In all the cases, PCV was higher than GCV indicating the influence of environment on the characters. High heritability coupled with high GA was observed for several plant traits; number of tillers, plant height, total number of spikelets panicle−1, biomass plant−1, straw weight, harvest index and grain yield plant−1 and hence offered good scope for selection. Grain yield plant−1 was found to be positively correlated with plant height, number of tillers, panicle length, panicle exsertion, number of panicles plant−1, single panicle weight, test weight, number of fertile spikelets panicle−1, straw weight, biomass plant−1, harvest index and grain breadth both at genotypic and phenotypic levels. Harvest index exerted maximum positive direct effect, followed by biomass plant−1 and straw weight on grain yield plant−1 at phenotypic level. Shapiro-Wilks “W test of normality” indicated that the population was skewed towards female parent IR50 for some traits and for some others towards Moroberekan, the male parent. Most of the characters that showed skewness were platykurtic with a kurtosis value of less than 3. 相似文献
12.
Byeong Chul Moon Seung Hyun Cho Oh Do Kwon Sun Gye Lee Byun Woo Lee Do Soon Kim 《Journal of Crop Science and Biotechnology》2010,13(2):121-126
Field experiments were conducted to investigate rice — Echinochloa crus-galli and rice — Eleocharis kuroguwai competition under transplanted rice cultivation in four major rice production areas; Suwon, Daejeon, Iksan, and Naju in Korea.
Rice yield data were used to predict rice yield as a function of plant densities of E. crus-galli and E. kuroguwai using a rectangular hyperbola and to determine economic threshold (ET) levels of the weeds. Both weed species significantly
reduced number of tillers at early rice growth stage, resulting in significant reduction in number of spikes, and the other
yield components such as number of grains, maturity and 1,000-grain weight at later growth stage. The weed competitivity represented
by parameter ranged from 0.0145 to 0.0346 for E. crus-galli and from 0.0037 to 0.0187 for E. kuroguwai, indicating that the competition effect of E. crus-galli on rice yield was slightly greater than that of E. kuroguwai. The ET values of E. crus-galli were between 0.298 and 1.078 plants m−2, while those of E. kuroguwai were between 0.848 and 5.298 plants m−2, depending on weed competitivity and herbicide price. Therefore, our results can be used to support decision-making on herbicide
application for E. crus-galli and E. kuroguwai management in transplanted rice cultivation. 相似文献
13.
Grain moisture in maize at harvest depends on the grain drying rate (GDR) after physiological maturity. The maize plants with high GDR can reduce grain moisture rapidly, which will shorten the drying time after harvest and prevent the grain to be mildew and enhance maize quality. In this study, A total of 280 recombinant inbred lines that were derived from a cross between Ji846 (high drying rate, 1.18 % day−1) and Ye3189 (slow drying rate, 0.39 % day−1) were used to construct genetic linkage map and identify QTL underlying GDR in different environments. A genetic linkage map was constructed containing 97 SSR and 49 AFLP markers, which covered 2356.8 cM of the maize genome, with an average distance of 16.1 cM. Composite interval mapping identified 14 QTL for GDR after physiological maturity located on chromosomes 2, 3, 5, 6 and 8. The additive effects of QTL were all from Ji846. The range of phenotypic variation explained by the QTL was 5.05–16.28 %. But only two QTL (qKdr-2-1, qKdr-3-6) were identified across both locations. qKdr-2-1 positioned between the markers phi090-umc1560 on chromosome 2 explained 15.59 % of the phenotypic variance, and the other qKdr-3-6 positioned between the markers phi046-bnlg1754 on chromosome 3 explained 10.28 % of the phenotypic variance. 相似文献
14.
Ning Li Jian Sun Jingguo Wang Hualong Liu Hongliang Zheng Luomiao Yang Yingpei Liang Xianwei Li Detang Zou 《Plant Breeding》2017,136(6):881-891
Alkaline stress causes injuries to rice seedlings in many parts of the world and is therefore an important factor affecting rice production in such areas. In this study, we preliminarily located quantitative trait loci (QTLs) for survival days of seedlings (SDS) and the concentrations of Na+ and K+ in shoots (SNC and SKC) and roots (RNC and RKC) under alkaline stress using an F2:3 population, which was derived from a cross between Caidao and WD20342 with 151 simple sequence repeat (SSR) markers. A total of seven QTLs were detected. Of these QTLs, qSNC3 had the largest effect, which explained 21.24% of the total phenotypic and is a major QTL. Next, a mapping population consisting of 190 BC2F2 plants was constructed using WD20342 as a donor parent to verify qSNC3. As a result, qSNC3 was delimited to an 81.7‐kb region between markers RM1221 and RM4404. In this region, LOC_Os03 g62500 and LOC_Os03 g62620 exhibited different expression between Caidao and WD20342 under alkaline stress. These results provide a basis for identifying genes related to alkaline tolerance in rice. 相似文献
15.
Mi-Young Kang Catherine W. Rico Sang-Chul Lee 《Journal of Crop Science and Biotechnology》2011,14(2):111-118
The physicochemical properties of pigmented (Midorimochi, Jeokjinjubyeo, and Heukmichalbyeo) and non-pigmented (Hwayoungbyeo)
rice varieties were investigated. Starch from non-pigmented rice consisted mainly of large polyhedral granules that were more
loosely packed than those of the non-pigmented sample. Pigmented rice showed higher linoleic acid content (36–40%) and hydrolysis
rate (63–79%) but lower oleic acid content (35–39%), blue value (0.05–0.17), and viscosity values than the non-pigmented one.
Significantly higher mineral content, blue value, and pasting and viscosity values were observed in the Jeokjinjubyeo sample
compared to those of the other pigmented rice samples. The Midorimochi variety, on the other hand, exhibited the highest total
amino acid (816.82 ng mg−1) and sugar (0.15–3.35 μg g−1) contents and the lowest pasting and viscosity values. No substantial difference in the X-ray diffraction pattern was observed
among the samples. Results of this study could serve as baseline information for the quality evaluation of three pigmented
rice cultivars and provide a better understanding of their potential uses and food industry applications. 相似文献
16.
以早籼稻浙106与近缘系浙205、浙206和浙207共4个品种(系)为研究对象,利用农艺性状为观测指标的形态标记鉴定技术和简单重复序列(SSR)分子标记鉴定技术对4个品种(系)的农艺性状和基因组DNA进行性状考查。结果表明:4个材料具有各自所特有的外观形态标记,但只运用农艺性状的观察很难来鉴定浙106与近缘系,选用的32对引物中有13对引物在品种(系)间表现明显的多态性特征,SSR标记结合形态标记用于近缘系间的品种鉴别较为合适。 相似文献
17.
Intergeneric sexual hybridizations were conducted between two genera of Rutaceae, with Satsuma mandarin (Citrus unshiu Marc) and Red tangerine (C. reticulata Blanco) as maternal parents, and Poncirus trifoliata (L.) Raf as the paternal parent, in an effort to generate hybrid populations for both molecular mapping and rootstock breeding.
Embryo rescue is important for citrus sexual breeding because polyembryony can interfere with hybrid embryo recovery. Immature
embryos of 80, 85, 90 days after pollination (DAP) from the Satsuma mandarin (S) × trifoliate orange (P) cross, 80 and 85
DAP from the Red tangerine (R) × trifoliate orange (P) cross, were cultured on MG1.0 medium consisting of MT basal medium
supplemented with 1.0 mg l−1 GA3 and 4% sucrose. The results showed that 80 DAP was the optimal time for embryo rescue of the tested crosses, as evidenced
by embryos at this stage exhibiting high germination rates, 37.3% for S × P and 51.3% for R × P. Among the eight tested media,
MT medium supplemented with 0.5 mg l−1 GA3 was the best one for Satsuma mandarin, and MT plus 1.0 mg l−1 GA3 for Red tangerine. A total of 85 plants were obtained from S × P, and 340 from R × P. Out of them, 44 progenies from S × P
and 111 from R × P were sufficiently confirmed to be hybrids by morphological characterization and SSR analysis. In addition,
two hybrid callus lines were obtained from S × P and R × P respectively. 相似文献
18.
Developing gene-tagged molecular markers for functional analysis of starch-synthesizing genes in rice (Oryza sativa L.) 总被引:1,自引:0,他引:1
Xinyan Liu Minghong Gu Yuepeng Han Qing Ji Jufei Lu Shiliang Gu Rong Zhang Xin Li Jianmin Chen Schuyler S. Korban Mingliang Xu 《Euphytica》2004,135(3):345-353
The granule-bound starch synthase(GBSS), starch branching enzymes 1 (SBE1)and 3 (SBE3) are major enzymes involved in starch
biosynthesis in rice endosperm. Available sequences of Sbe1 and Sbe3 genes encoding corresponding SBE1 and SBE3 have been used to identify homologous regions from genome databases of both the
indica rice 93-11 and the japonica rice Nipponbare. Sequence diversities were exploited to develop gene-tagged markers to distinguish an indica allele from a japonica allele for both Sbe1 and Sbe3 loci. With these newly developed gene-tagged markers and available Wx gene markers, the roles of these starch-synthesizing genes (Sbe1, Sbe3, and Wx) in determining amylose content (AC) in the rice endosperm were evaluated using a double-haploid (DH)population derived from
a cross between the indica rice cv. Nanjing11 and the japonica rice cv. Balilla. Only the Wx and Sbe3 loci had significant effects on the AC variation. On average, indica Wx
a genotypes showed ∼9.1% higher AC than japonica Wx
b genotypes, while indica Sbe3
a genotypes showed ∼1.0% lower AC than japonica Sbe3
b genotypes. A significant interaction was also observed between Wx and Sbe3 loci whereby the amylose content was 0.3% higher in Sbe3
a than Sbe3
b genotypes in the presence of the Wx
a allele, but it was lower by 2.3% in the presence of the Wx
b allele. Overall, polymorphisms at the Wx and Sbe3 loci together could account for 79.1% of the observed AC variation in the DH population. The use of gene-tagged markers in
marker-assisted selection and gene functional analysis was also discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
The data presented herein reports a rapid and efficient method for direct plant regeneration at high frequency without intervening
callus formation from shoot tip (93%) and nodal segment (60%) cultured on MS media supplemented with 0.5 mg l−1 KIN, 0.25 mg l−1 BAP, 0.1 mg l−1 IAA and 100 mg l−1 CH. Conversely, leaf and internodal explants were poorly responsive. Adventitious shoot buds arose not only from the cut
ends but all along the surface of the explants leading to the formation of clusters with multiple shoots. Multiple shoots
upon transfer to MS media supplemented with 2.0 mg l−1 IBA induced efficient rooting (80%). In vitro flowering was observed when tissue culture-raised plantlets were maintained for extended period in culture. Shikonin was
induced in roots of regenerated plants which often exudates in the culture medium was quantified spectrophotometerically by
recording absorbance at 620 nm and estimated to be 0.50 mg g−1 fresh weight of tissue at the end of the 50 days of culture. The regenerated plants were successfully acclimatized, hardened,
and transferred to soil in green house for micropropagation. The protocol developed here will be very useful for the supply
of Arnebia hispidissima all year as a raw product necessary for obtaining Shikonin for the cosmetic, dyeing, food, and pharmaceutical industries. 相似文献
20.
Bhawna Saxena Rajinder Kaur Satya Vrat Bhardwaj 《Journal of Crop Science and Biotechnology》2011,14(3):191-196
Genetic relationship and diversity among seven cabbage cultivars were analyzed using RAPD and SSR markers. These cultivars
are of great commercial value in India and are confirmed for their reaction to black rot caused by Xanthomonas campestris pv. campestris. However, so far the extent of genetic diversity and relatedness has not been studied in these cultivars. A total of 17 selected
RAPD primers generated 90 bands, 76 of which were polymorphic (84.44%). In addition, 27 selected SSR primers generated 67
amplified bands with 59 of which were polymorphic (87.6%). Though both the marker techniques were able to discriminate the
cultivars effectively, analysis of combined data of markers (RAPD and SSR) resulted in better distinction of cultivars. By
combining both the markers, a total of 157 bands were detected of which 135 bands (85.98%) were polymorphic, i.e. an average
of 5.95 bands per primer. High level of polymorphism (> 85%) recorded with two different marker systems indicated a high level
of genetic variation existing among the cultivars. Genetic relationship estimated using similarity co-efficient (Jaccard’s)
values between different pairs of cultivars varied from 0.21 to 0.77 in RAPD, 0.42 to 0.82 in SSR, and 0.43 to 0.89 with combined
markers. A high correspondence had been recorded between the values of genetic variations generated by UPGMA, clustering,
and scatter plot diagrams. The cultivars ‘January King Sel. Improved’ and ‘Golden Acre’ are highly divergent cultivars as
demonstrated by both the marker systems. 相似文献