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1.
A new wheat-Thinopyrum substitution line AS1677, developed from a cross between wheat line ML-13 and wheat-Thinopyrum intermedium ssp. trichophorum partial amphiploid TE-3, was characterized by fluorescence in situ hybridization (FISH), sequential Giemsa-C banding, genomic
in situ hybridization (GISH), seed storage protein electrophoresis, molecular marker analysis and disease resistance screening.
Sequential Giemsa-C banding and GISH using Pseudoroegneria spicata genomic DNA as probe indicated that a pair of St-chromosomes with strong terminal bands were introduced into AS1677. FISH
using pTa71 as a probe gave strong hybridization signals at the nuclear organization region and in the distal region of the
short arms of the St chromosome. Moreover, FISH using the repetitive sequence pAs1 revealed that a pair of wheat 1D chromosomes
was absent in accession AS1677. Seed storage proteins separated by acid polyacrylamide gel electrophoresis (APAGE) and sodium
dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) confirmed that AS1677 lacked the gliadin and glutenin bands
encoded by Gli-D1 and Glu-D1, further confirming the absence of chromosome 1D. The introduced St chromosome pair belonging to homoeologous group 1 was
identified by newly produced genome specific markers. AS1677 is a new 1St (1D) substitution line. When inoculated with stripe
rust and powdery mildew isolates, AS1677 expressed stripe rust resistance possibly derived from its Thinopyrum parent. AS1677 can be used as a donor source for introducing novel disease resistance genes to wheat in breeding programs
aided by molecular and cytogenetic markers. 相似文献
2.
Tolerance to low temperature is an important prerequisite for optimal performance of peanut (Arachis hypogaea L.) in a number of temperate peanut-growing environments. One hundred fifty-eight peanut accessions belonging to five botanical
types, known to be tolerant to low temperature (12°C) at germination, were evaluated for phenotypic diversity for 15 morphological
traits in the 2001 rainy season and for 15 agronomic and two seed quality traits in the 2001 rainy and 2001/2002 post-rainy
seasons. Analysis of data, using the residual maximum-likelihood approach indicated that variance components due to genotypes
were significant for all traits in the rainy and for all but two traits in the post-rainy season. Clustering based on scores
of nine principle components delineated four clusters. The cold-tolerant genotypes and the standard control cultivars in the
four clusters differed in mean, variance, and range both during rainy and post-rainy seasons for a range of agronomic traits,
indicating the diversity among the clusters. The cold-tolerant accessions were superior to control cultivars for several agronomic
traits compared with their respective controls in both the rainy and post-rainy seasons, so their use in breeding should result
in genetically diverse cold-tolerant high-yielding peanut cultivars. 相似文献
3.
Groundnut (Arachis hypogaea L.) is an important oilseed crop grown in more than 100 countries across wide range of environments. Frequent occurrence
of drought is one of the limiting factors adversely affecting groundnut productivity, especially in rainfed areas, and hence
genotypes having high water use efficiency (WUE) under limited available water need to be developed. In groundnut, WUE is
correlated with SPAD chlorophyll meter reading (SCMR) and specific leaf area (SLA). These two traits, SCMR and SLA, can be
used as surrogate traits for selecting for WUE. In order to improve SCMR and SLA, and in turn WUE in groundnut, a good knowledge
of the genetic system controlling the expressions of these traits is essential for the selection of the most appropriate and
efficient breeding procedure. The present investigation was conducted to determine the gene action controlling the inheritance
of SCMR and SLA in two crosses, ICG 7243 × ICG 9418 and ICG 6766 × Chico, and their reciprocals. Six generations of each cross
(P1, P2, F1, F2, BC1P1, and BC1P2) were evaluated for SCMR and SLA at two stages of the crop growth viz., 60 and 80 days after sowing (DAS). For SCMR at 80
DAS, additive effects were important in both the crosses whereas predominance of dominance effects with duplicate epistasis
was observed for SCMR at 60 DAS and SLA at both stages in both the crosses. Predominance of additive effect for SCMR at 80
DAS suggested effective selection could be practiced even in early generations whereas for SCMR at 60 DAS and SLA at both
stages in both crosses, it would be better to defer selection to later generations. Further, recording of SCMR and SLA should
be done between 60 and 80 DAS for screening the germplasm lines for drought tolerance. 相似文献
4.
Yingjie Li Lanzhou Li Xiurong Zhang Kun Zhang Dengchao Ma Jiaqi Liu Xiaojun Wang Fengzhen Liu Yongshan Wan 《Euphytica》2017,213(2):57
Main stem height (MSH) and the first lateral branch length (LBL) of peanut (Arachis hypogaea L.) are important traits affecting plant shape and yield. Identification of quantitative trait loci (QTLs) related to these two traits, the prediction and cloning of candidate genes, and identification of plant height-related molecular markers are the basis for analysis of the molecular genetic mechanism of plant shape in peanut. In this study, a population of 151 recombinant inbred lines from a single seed, derived from a cross between variety 79266 (P1) and its variant progeny D893 (P2), was used to construct a peanut genetic map. The map consisted of 231 simple sequence repeat markers in 23 linkage groups, had a total length of 905.18 cM with average and minimum marker intervals of 3.92 and 0.1 cM, respectively. There were 11 and 16 QTLs detected in six environments for MSH and LBH with 6.26–22.53 and 5.89–21.63% phenotypic variation explained (PVE), respectively. Seven QTLs were detected in two or more environments: 3 QTLs for MSH (including Qmsh-14-3) with 7.66–22.53% PVE, and 4 QTLs for LBL (including Qllb-11-1) with 6.12–21.63% PVE. Qmsh-14-3 was steadily detected in five environments, localized between two markers, ARS376 and SEQ4G02, exhibited a genetic distance of 0.59–2.59 and 4.11–6.11 cM from the two markers, respectively. Qllb-11-1 was steadily detected in five environments, localized between two markers, ARS203 and AHS1413, exhibited a genetic distance of 1.06–3.06 and 0.23–2.23 cM from the two markers, respectively. There were 220 germplasm accessions used to detect the relationship between genotype and phenotypic values of traits at the marker loci ARS376 and SEQ4G02, average values of MSH and LBL were significantly higher for germplasm with the P1 compared to the P2 genotype. Determination of the marker loci ARS203 and AHS1413 indicated that average values of LBL were greater in germplasm with the P1 than the P2 genotype. The results provide references for fine mapping of QTLs for MSH and LBL, as well as breeding optimum plant-types in peanut. 相似文献
5.
Sandip K. Bera Jignesh H. Kamdar Swati V. Kasundra Pitabas Dash Anil K. Maurya Mital D. Jasani Ajay B. Chandrashekar N. Manivannan R. P. Vasanthi K. L. Dobariya Manish K. Pandey Pasupuleti Janila T. Radhakrishnan Rajeev K. Varshney 《Euphytica》2018,214(9):162
Peanut plays a key role to the livelihood of millions in the world especially in Arid and Semi-Arid regions. Peanut with high oleic acid content aids to increase shelf-life of peanut oil as well as food products and extends major health benefits to the consumers. In peanut, ahFAD2 gene controls quantity of two major fatty acids viz, oleic and linoleic acids. These two fatty acids together with palmitic acid constitute 90% fat composition in peanut and regulate the quality of peanut oil. Here, two ahfad2 alleles from SunOleic 95R were introgressed into ICGV 05141 using marker-assisted selection. Marker-assisted breeding effectively increased oleic acid and oleic to linoleic acid ratio in recombinant lines up to 44% and 30%, respectively as compared to ICGV 05141. In addition to improved oil quality, the recombinant lines also had superiority in pod yield together with desired pod/seed attributes. Realizing the health benefits and ever increasing demand in domestic and international market, the high oleic peanut recombinant lines will certainly boost the economical benefits to the Indian farmers in addition to ensuring availability of high oleic peanuts to the traders and industry. 相似文献
6.
7.
Furong Wang Yongchao Gong Chuanyun Zhang Guodong Liu Liuming Wang Zhenzhen Xu Jun Zhang 《Euphytica》2011,181(1):41-53
The germplasm with exotic genomic components especially from Sea Island cotton (Gossypium barbadense L. Gb) is the dominant genetic resources to enhance fiber quality of upland cotton (G. hirsutum L., Gh). Due to low efficiency of phenotypic evaluation and selection on fiber quality, genetic dissection of favorable alleles
using molecular markers is essential. Genetic dissection on putative Gb introgressions related to fiber traits were conducted by SSR markers with mapping populations derived from a cross between
Luyuan343 (LY343), a superior fiber quality introgression line (IL) with genomic components from Gb, and an elite Upland cotton cv. Lumianyan#22 (LMY22). Among 82 polymorphic loci screened out from 4050 SSRs, 42 were identified
as putative introgression alleles. A total of 29 fiber-related QTLs (23 for fiber quality and six for lint percentage) were
detected and most of which clustered on the putative Gb introgression chromosomal segments of Chr.2, Chr.16, Chr.23 and Chr.25. As expected, a majority of favorable alleles of fiber
quality QTLs (12/17, not considering the QTLs for fiber fineness) came from the IL parent and most of which (11/12) were conferred
by the introgression genomic components while three of the six (3/6) favorable alleles for lint percentage came from the Gh parent. Validation of these QTLs using an F8 breeding population from the same cross made previously indicated that 13 out of 29 QTLs showed considerable stability. The
results suggest that fiber quality improvement using the introgression components could be facilitated by marker-assisted
selection in cotton breeding program. 相似文献
8.
Striga is an important parasitic weed causing substantial economic losses in cereal and legume crop production in sub-Saharan Africa. Integrated Striga management approaches such as a combined use of Striga resistant varieties and Fusarium oxysporum f.sp. strigae (FOS), a biocontrol agent of Striga, are an option to control the parasite and to boost sorghum productivity. Understanding host gene action influencing Striga resistance, with or without FOS treatment, is key to developing improved sorghum varieties with durable resistance and high yield. The objective of this study was to determine the gene action and inheritance of Striga resistance using genetically diverse populations of sorghum involving FOS treatment. Twelve sorghum parents selected for Striga resistance, FOS compatibility or superior agronomic performances were crossed using a bi-parental mating scheme. The selected male and female parents and their F1 progenies, backcross derivatives and the F2 segregants were field evaluated at three locations in Tanzania known for their severe Striga infestations using a lattice experimental design with two replications. The following data were collected and subjected to generation mean analysis (GMA): days-to-50% flowering (DFL), seed yield per plant (SYP) and number of Striga per plant (SN). GMA showed the preponderance of additive genetic action contributing to the total genetic variation in the evaluated sorghum populations. The additive genetic effect for DFL, SYP and SN, with and without FOS treatments, ranged from 72.02 to 86.65% and 41.49 to 95.44%, 75.62 to 91.42% and 71.83 to 91.89%, and 77.35 to 93.56% and 72.86 to 95.84%, in that order. The contribution of non-additive genetic effects was minimal and varied among generations. FOS application reduced DFL and SN and improved SYP in most of the tested sorghum populations. DFL of sorghum populations was reduced by a mean of 8 days under FOS treatment compared to the untreated control in families such as 675 × 654, AS435 × AS426 and 1563 × AS436. FOS treatment improved SYP with a mean of 6.44 g plant?1 in 3424 × 3993 and 3984 × 672. The numbers of Striga plants were reduced with a mean of 16 plants due to FOS treatment in the crosses of 675 × 654, 1563 × AS436, 4567 × AS424, and 3984 × 672. The study demonstrated that additive genes were predominantly responsible for the inheritance of Striga resistance in sorghum. Pure line cultivar development targeting reduced DFL, SN and high SYP in the selected populations may provide enhanced response to selection for integrated Striga management (ISM) programme. 相似文献
9.
Ana Delia Gisbert Carlos Romero José Martínez-Calvo Carmen Leida Gerardo Llácer María Luisa Badenes 《Euphytica》2009,168(1):121-134
Loquat (Eriobotrya japonica (Thunb.) Lindl.) is a minor Rosaceae fruit of growing interest as an alternative to the main fruit crops. In this context,
the selection of new cultivars to satisfy the market demand will request the suitable characterization of the available germplasm.
In this work, genetic relationships among 83 loquat accessions from different countries belonging to the European loquat germplasm
collection, held at the Instituto Valenciano de Investigaciones Agrarias (IVIA) in Moncada (Spain) were evaluated using microsatellites
and S-allele fragments. A total of nine single sequence repeats (SSRs) from Malus and Eriobotrya genera revealed 53 informative alleles and the S-RNases consensus primers detected 11 self-incompatibility putative alleles. The combined data allow to distinguish unambiguously
80 out of the 83 accessions studied. Unweighted pair-group method (UPGMA) cluster and principal coordinates analysis (PCoA),
based on Dice’s genetic distance, generally grouped genotypes according to their geographic origins and pedigrees. Discrepancies
and similarities of the results obtained with other variability analysis, based on pomological traits or molecular markers,
on the same loquat collection are discussed. 相似文献
10.
11.
Jundae Lee Jae Bok Yoon Jung-Heon Han Won Phil Lee Sang Hoon Kim Hyo Guen Park 《Euphytica》2010,173(1):55-61
Genic male sterility (GMS) has long been used as a tool for hybrid seed production in chili pepper (Capsicum annuum L.). We developed DNA markers linked to the GMS ms
3
gene in a segregating population using bulked segregant analysis (BSA) and amplified fragment length polymorphism (AFLP)
techniques. The segregating population was subjected to BSA-AFLP with 512 primer combinations. Three AFLP markers (Eagg/Mccc276, Eagc/Mctt178, and Ecag/Mtgc204) were identified as tightly linked to the ms
3
locus. Among them, we converted the AFLP marker Ecag/Mtgc204 to the cleavage amplified polymorphic sequence (CAPS) marker, named GMS3-CAPS, based on sequencing analysis of internal and
flanking regions for the markers between male-fertile and sterile plants. This marker will be useful for pepper breeding using
the GMS system. 相似文献
12.
In a previously made cross Brassica napus cv. Oro (2n = 38) × Capsella bursa-pastoris (2n = 4x = 32), one F1 hybrid with 2n = 38 was totally male sterile. The hybrid contained no complete chromosomes from C. bursa-pastoris, but some specific AFLP (amplified fragment length polymorphism) bands of C. bursa-pastoris were detected. The hybrid was morphologically quite similar to ‘Oro’ except for smaller flowers with rudimentary stamens
but normal pistils, and showed good seed-set after pollination by ‘Oro’ and other B. napus cultivars. The fertility segregation ratios (3:1, 1:1) in its progenies indicated that the male sterility was controlled
by a single recessive gene. In the pollen mother cells of the male sterile hybrid, chromosome pairing and segregation were
normal. Histological sectioning of its anthers showed that the tapetum was multiple layers and was hypertrophic from the stage
of sporogenic cells, and that the tetrads were compressed by the vacuolated and disaggregated tapetum and no mature pollen
grains were formed in anther sacs, thus resulting in male sterility. The possible mechanisms for the production of the male
sterile hybrid and its potential in breeding are discussed. 相似文献
13.
Junghyun Shim Olivier Panaud Clémentine Vitte Merlyn S. Mendioro Darshan S. Brar 《Euphytica》2010,176(2):269-279
Molecular markers have been successfully used in rice breeding however available markers based on Oryza
sativa sequences are not efficient to monitor alien introgression from distant genomes of Oryza. We developed O. minuta (2n = 48, BBCC)-specific clones comprising of 105 clones (266–715 bp) from the initial library composed of 1,920 clones against
O. sativa by representational difference analysis (RDA), a subtractive cloning method and validated through Southern blot hybridization.
Chromosomal location of O. minuta-specific clones was identified by hybridization with the genomic DNA of eight monosomic alien additional lines (MAALs). The
37 clones were located either on chromosomes 6, 7, or 12. Different hybridization patterns between O. minuta-specific clones and wild species such as O. punctata, O. officinalis, O. rhizomatis, O. australiensis, and O. ridleyi were observed indicating conservation of the O. minuta fragments across Oryza spp. A highly repetitive clone, OmSC45 hybridized with O. minuta and O. australiensis (EE), and was found in 6,500 and 9,000 copies, respectively, suggesting an independent and exponential amplification of the
fragment in both species during the evolution of Oryza. Hybridization of 105 O. minuta specific clones with BB- and CC-genome wild Oryza species resulted in the identification of 4 BB-genome-specific and 14 CC-genome-specific clones. OmSC45 was identified as a fragment of RIRE1, an LTR-retrotransposon. Furthermore this clone was introgressed from O. minuta into the advanced breeding lines of O. sativa. 相似文献
14.
Pseudomonas syringae is the main pathogen responsible for bacterial blight disease in pea and can cause yield losses of 70%. P. syringae pv. pisi is prevalent in most countries but the importance of P. syringae pv. syringae (Psy) is increasing. Several sources of resistance to Psy have been identified but genetics of the resistance is unknown. In this study the inheritance of resistance to Psy was studied in the pea recombinant inbred line population P665 × ‘Messire’. Results suggest a polygenic control of the resistance and two quantitative trait loci (QTL) associated with resistance, Psy1 and Psy2, were identified. The QTL explained individually 22.2 and 8.6% of the phenotypic variation, respectively. In addition 21 SSR markers were included in the P665 × ‘Messire’ map, of which six had not been mapped on the pea genome in previous studies. 相似文献
15.
Thierry Pascal Romain Aberlenc Carole Confolent Mathilde Hoerter Elodie Lecerf Christophe Tuéro Patrick Lambert 《Euphytica》2017,213(6):132
Peach powdery mildew is one of the major diseases of the peach. Various sources of resistance to PPM have thus been identified, including the single dominant locus Vr2 carried by the peach rootstock ‘Pamirskij 5’. To map Vr2, a linkage map based on microsatellite markers was constructed from the F2 progeny (WP2) derived from the cross ‘Weeping Flower Peach’ × ‘Pamirskij 5’. Self-pollinations of the parents were also performed. Under greenhouse conditions, all progenies were scored after artificial inoculations in two classes of reactions to PPM (resistant/susceptible). In addition to Vr2, WP2 segregated for three other traits from ‘Weeping Flower Peach’: Rm1 for green peach aphid resistance, Di2 for double-flower and pl for weeping-growth habit. With their genomic locations unknown or underdocumented, all were phenotyped as Mendelian characters and mapped: Vr2 mapped at the top of LG8, at 3.3 cM, close to the CPSCT018 marker; Rm1 mapped at the bottom of LG1, at a position of 116.5 cM, cosegregating with the UDAp-467 marker and in the same region as Rm2 from ‘Rubira’®; Di2 mapped at 28.8 cM on LG6, close to the MA027a marker; and pl mapped at 44.1 cM on LG3 between the MA039a and SSRLG3_16m46 markers. Furthermore, this study revealed, for the first time, a pseudo-linkage between two traits of the peach: Vr2 and the Gr locus, which controls the red/green color of foliage. The present work therefore constitutes a significant preliminary step for implementing marker-assisted selection for the four major traits targeted in this study. 相似文献
16.
Lu Xiao Bin Yi Yufeng Chen Zhen Huang Wei Chen Chaozhi Ma Jinxing Tu Tingdong Fu 《Euphytica》2008,164(2):377-384
7–7365AB is a recessive genic male sterile (RGMS) two-type line, which can be applied in a three-line system with the interim-maintainer,
7–7365C. Fertility of this system is controlled by two duplicate dominant epistatic genes (Bn;Ms3 and Bn;Ms4) and one recessive epistatic inhibitor gene (Bn;rf). Therefore an individual with the genotype of Bn;ms3ms3ms4ms4Rf_ exhibits male sterility, whereas, plant with Bn;ms3ms3ms4ms4rfrf shows fertility because homozygosity at the Bn;rf locus (Bn;rfrf) can inhibit the expression of two recessive male sterile genes in homozygous Bn;ms3ms3ms4ms4 plant. A cross of 7–7365A (Bn;ms3ms3ms4ms4RfRf) and 7–7365C (Bn;ms3ms3ms4ms4rfrf) can generate a complete male sterile population served as a mother line with restorer in alternative strips for the multiplication
of hybrid seeds. In the present study, molecular mapping of the Bn;Rf gene was performed in a BC1 population from the cross between 7–7365A and 7–7365C. Bulked segregant analysis (BSA) and amplified fragment length polymorphism
(AFLP) technique was used to identify molecular markers linked to the gene of interest. From a survey of 768 primer combinations,
seven AFLP markers were identified. The closest marker, XM5, was co-segregated with the Bn;Rf locus and successfully converted into a sequence characterized amplified region (SCAR) marker, designated as XSC5. Two flanking
markers, XM3 and XM2, were 0.6 cM and 2.6 cM away from the target gene, respectively. XM1 was subsequently mapped on linkage
group N7 using a doubled-haploid (DH) mapping population derived from the cross Tapidor × Ningyou7, available at IMSORB, UK.
To further confirm the location of the Bn;Rf gene, additional simple sequence repeat (SSR) markers in linkage group N7 from the reference maps were screened in the BC1 population. Two SSR markers, CB10594 and BRMS018, showed polymorphisms in our mapping population. The molecular markers found
in the present study will facilitate the selection of interim-maintainer. 相似文献
17.
Yaowalak Na-ek Arunee Wongkaew Thitaporn Phumichai Nongluck Kongsiri Rungsarid Kaveeta Tanee reewongchai Chalermpol Phumichai 《Journal of Crop Science and Biotechnology》2011,14(2):105-110
Ten microsatellite markers were used to investigate genetic diversity and genetic structure among 32 accessions of Jatropha curcas. Low levels of average genetic diversity were observed (H
E
= 0.160). A dendrogram produced by the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) based on Nei’s genetic distances
revealed 3 groups among 32 accessions. The genetic differentiation (F
ST
) among two groups was significant (P < 0.01). The model-based Bayesian clustering method indicated that a population structure (ΔK) was separated into two groups. The analysis of molecular variance (AMOVA) showed higher variability (63.753%) among groups
than within groups (36.247%). These findings could assist in defining the best method of genetic conservation and studies
in breeding programs for genetic improvement of J. curcas. 相似文献
18.
Chaozhi Ma Chunyan Li Yongqiang Tan Wei Tang Jianfeng Zhang Changbin Gao Tingdong Fu 《Euphytica》2009,166(1):123-129
A self-incompatible (SI) line, S-1300, and its maintainer 97-wen135, a self-compatible (SC) line, were used to study the inheritance
of maintenance for self-incompatibility in B. napus. The ratio of SI plants to SC plants from S-1300 × 97-wen135 F2 and (S-1300 × 97-wen135) × 97-wen135 was 346:260 and 249:232, fitting the expected ratio of 9:7 and 1:1, respectively. Based
on these observations, here we propose a genetic model in which two independent loci, S locus and S suppressor locus (sp), are predicted to control the inheritance of maintenance for self-incompatibility in B. napus. The genotypes of S-1300 and 97-wen135 are S
1300
S
1300
sp
1300
sp
1300
and S
135
S
135
sp
135
sp
135
, respectively. S
135
is dominant to S
1300
, but coexistence of sp
1300
and sp
135
fails to suppress S locus. Both S
1300
and S
135
can be suppressed by sp
135
, while sp
1300
can suppress S
135
but not S
1300
. The model contains two characteristics: that a dominant S locus exists in self-compatible B. napus, and that co-suppression will occur when sp loci are heterozygous. The model has been validated by the segregation of S phenotypes in the (S-1300 × 97-wen135) × S-1300, the progenies of SC S-1300 × 97-wen135 F2 plants and DH population developed from S-1300 × 97-wen135 F1. This is the first study to report co-suppression of S suppressor loci in B. napus. The genetic model will be very useful for developing molecular markers linked to maintenance for self-incompatibility and
for dissecting the mechanism of SI/SC in B. napus. 相似文献
19.
Dragan Milić Slobodan Katić Đura Karagić Jelica Gvozdanović–Varga Sofija Petrović Jan Boćanski 《Euphytica》2011,182(1):25-33
The objective of this study was to develop diallel population hybrids by crossing selected germplasm and to determine the
gene effects and genetic control of yield and yield components using diallel analysis. A complete diallel including reciprocals
was made during 2003 and 2004 between five alfalfa cultivars of different geographic origin. For each pairwise cross, five
plants were chosen at random from each of the two cultivars (~100 florets per plant) to obtain the F1 generation. A spaced plant field was established in 2006 which included the five alfalfa cultivars (parents) and their 20
diallel hybrids (F1). The results of the diallel analysis suggest that the genetic control of major agronomic traits is determined by both additive
gene action (accumulation of frequency of desirable alleles represented by significant GCA effects) and nonadditive gene action
(complementary gene interactions represented by significant SCA effects). This type of gene action expression in alfalfa also
determines the way in which breeding is carried out and brings about changes in the methods used and has given rise to the
idea of the semi-hybrid breeding of this crop. The concept involves: breeding alfalfas within the population, identification
of heterotic germplasm, and the production of seed of the population hybrid (PH). 相似文献
20.
J. B. Hartman D. Vuylsteke P. R. Speijer F. Ssango D. L. Coyne D. De Waele 《Euphytica》2010,172(1):139-148
Crop growth and damage parameters (plant growth and yield, root damage and nematode population densities), believed to be
associated with resistance of Musa genotypes to nematodes under field conditions, were evaluated in a field trial of 24 Musa genotypes inoculated at planting with a combination of Radopholus similis and Helicotylenchus multicinctus with the objective to identify parameters with strong association with nematode resistance and high heritability. Correlation
and path analysis of the association between plant growth, yield, root damage and nematode population densities showed a strong
negative association between percentage dead roots, percentage root necrosis, R. similis and H. multicinctus population densities and yield. The strongest negative association was observed between percentage dead roots and yield.
Broad-sense genotype heritability estimates demonstrated that heritability estimates for percentage dead roots, number of
large lesions and nematode population density were most affected by inoculation with nematodes. These results indicate therefore
that effective selection for nematode resistance under field conditions could be obtained by using an index, that includes
percentage dead roots, the number of large lesions, and nematode population density. 相似文献