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1.
Nadeem Khan Shujun Zhou M. S. Ramanna Paul Arens Jeronimo Herrera Richard G. F. Visser Jaap M. Van Tuyl 《Euphytica》2009,166(3):399-409
Ploidy level and intergenomic recombination was studied in interspecific hybrids between Longiflorum × Asiatic lilies (LA
hybrid) backcross to Asiatic parents in order to assess the possibility for analytic breeding in lily. By backcrossing the
diploid (2n = 2x = 24) F1 interspecific hybrid between Longiflorum × Asiatic lilies to Asiatic parents, 104 BC1 progeny plants were produced.
Among these, there were 27 diploids, 73 triploids (2n = 2x = 36) and 4 aneuploids (2x − 1, 2x + 2 or 2x + 3). In addition, by backcrossing triploid BC1 (LAA) plants to diploid Asiatic parents in 2x − 3x and reciprocal combinations, 14 diploid BC2 progenies were produced. Genomic in situ hybridization (GISH) was performed to
study the intergenomic recombination and karyotype composition. GISH indicated extensive intergenomic recombination among
the chromosomes in LA hybrids. A large number of Longiflorum chromosomes were transmitted to the BC1 progenies from LA hybrids.
However, very few Longiflorum chromosomes were transmitted from the BC1 triploid (LAA) plants to the BC2 progenies. The occurrence
of diploid plants in the BC progenies of LA hybrids has opened the prospects of analytic breeding in lilies. In this approach,
the selection of superior genotypes can be carried out at the diploid level and polyploid forms are synthesized from superior
diploid parents. The advantages of analytic breeding are evident: (a) a maximum level of heterozygosity can be attained in
the synthetic polyploids and (b) introgression can be achieved with a minimum of linkage drag. Based on GISH results the potential
application of analytic breeding in lily allopolyploids has been discussed. 相似文献
2.
About 19 cultivars, which had originated from backcrosses between F1 LA (Longiflorum × Asiatic) hybrids (2n = 2x = 24) as
female parents and Asiatic cultivars as male parents (2n = 2x = 24), were analyzed with genomic in situ hybridization. 17
of them were triploid (2n = 3x = 36), and two aneuploid (2n = 3x + 1 = 37). The triploid cultivars had resulted from the functional
2n eggs produced by the female parents (F1 hybrids) because first division restitution (FDR) occurred in their meiosis during
megasporogenesis. Similarly, the aneuploid cultivars had originated from viable 2n + 1 eggs. The extra chromosome in cultivar
041555 or 041572 resulted from one univalent or one half-bivalent which might have lagged behind when the sister chromatids
of the other univalents and half-bivalents were segregating during the FDR process in their LA hybrid parents, respectively.
That the majority of cultivars possessed recombinant chromosomes showed that intergenomic recombination might play an important
role during the selection of the cultivars directly from BC1 progenies. That five cultivars of the 15 recombinant cultivars
only had reciprocal recombinant chromosomes and 10 cultivars had non-reciprocal recombinant chromosomes indicates that the
latter are more important. Because 9 of the 10 non-reciprocal recombinant cultivars possessed substitutions for recombinant
segments, it also indicated that such substitutions could be an important source for the genetic variation in the sexual triploid
BC1 progenies. In such cases there was a potential for the expression of the recessive genes of the backcross parent in a
nulliplex (aaa) condition in the substituted segments. Genetic variation resulting from such nulliplex loci might have played
a role in the selection of some of the cultivars. 相似文献
3.
Lilium are Fritillaria-type plants. Triploid lilies, regardless of their male sterility, can be used as female parents to cross
with appropriate males, in contrast to other triploid Polygonum-type plants, which are usually seedless. Up to now, however,
little attention has been paid to the reason. Here we made allotriploid × diploid/tetraploid crosses in Lilium. Endosperm and progenies of LAA × AA/AAAA crosses were analyzed for ploidy level and genome composition. The endosperm of
some LAA × AA/AAAA ovules developed well but there was little or no development of LAA × LL/OO endosperm. The endosperm genome
composition of LAA × AA, LAA × AAAA, LAA × LL, LAA × OO are theoretically derived as 5A + 2L, 6A + 2L, 4A + 3L, 4A + 2L + O,
respectively. Genomic in situ hybridization showed that the progenies of LAA × AA/AAAA were aneuploid. Based on the experimental
results and analyses, our hypothesis is that five same genomes of endosperms are essential for its development in triploid × diploid/tetraploid
crosses of Lilium. The hypothesis can explain the success or failure of 3x × 2x/4x crosses in Lilium and is of importance for lily breeders who need to know the likelihood of success when producing new cultivars of this economically
important horticultural crop. 相似文献
4.
Nigel A. R. Urwin 《Euphytica》2014,196(3):331-339
Double podding in cultivated chickpeas (Cicer arietinum L.) can increase yield and yield stability. In the present study, we performed reciprocal crosses of ‘kabuli’ (double podded) and ‘desi’ (single podded) chickpeas to determine (i) the expressivity and penetrance of double podding, (ii) the correlations of yield and yield components, and (iii) the heritability of double podding, flower color, and stem pigmentation in F2 plants. Reciprocal crosses were performed with two genotypes, AC 2969 (kabuli) and ICC 4969 (desi), to generate F1 and F2 plants. The results indicated hybrid vigor (heterosis) for yield in F1 plants and better performance of F2 plants. Yield and yield components of some lines in F2 were superior to the best parent, indicative of transgressive segregation. In particular, the presence of double podding (‘s’ allele) significantly increased yield in some of the transgressive segregants. Expressivity and penetrance of the ‘s’ allele depends on the background of the female parent. Some of the double podding progeny had greater seed yields than those of the single podding progeny and greater seed yields than the best parents. Double podding, stem pigmentation, and pink flowers each appears to be governed by a single recessive gene. Stem pigmentation and pink flowers appear to be linked traits that depend on the genetic background of the crossed chickpeas. Taken together, our studies of reciprocal crosses of kabuli and desi chickpeas clearly showed that yield could be improved by selection for transgressive phenotypes that have double podding. 相似文献
5.
Lee T. Hickey Mark J. Dieters Ian H. DeLacy Mandy J. Christopher Olena Y. Kravchuk Phillip M. Banks 《Euphytica》2010,172(2):183-195
Pre-harvest sprouting (PHS) in wheat (Triticum aestivum L.) is a significant problem. Introgression of genes controlling grain dormancy into white-grained bread wheat is one means
of improving resistance to PHS. In this study seven dormant (containing the SW95-50213 and AUS1408 sources) × non-dormant
crosses were produced to investigate the effectiveness of selection for grain dormancy in early segregating generations. Each
generation (F1–F4) was grown in a temperature controlled glasshouse with an extended photoperiod (i.e. continuous light). F2 and F3 generations were subject to selection. Five hundred harvest-ripe grains were tested for germination over a 14 day period,
and the 100 most dormant grains were retained and grown-on to produce the next generation within each cross. The response
to selection was assessed through analysis of the time to 50% germination (G50) in the F2, F3 and F4 generations. In addition, changes in marker class frequencies for two SSR markers (barc170 and gpw2279) flanking a known
quantitative trait locus (QTL) for grain dormancy on chromosome 4A were assessed in DNA from F2 plants selected from early germinating (non-dormant) and late germinating (dormant) phenotypic extremes within each cross.
Selection for grain dormancy in the F2 and F3 generations effectively recovered the dormant phenotype in all seven crosses, i.e. the F4 generation was not significantly different from the dormant parent. Further, selection based on individual F2 grains changed marker class frequencies for the 4A dormancy QTL; in most cases eliminating the marker class homozygous for
the non-dormant alleles. Application of this screening method will enable breeders to better select for grain dormancy and
may lead to development of new cultivars offering effective resistance to PHS in the near future. 相似文献
6.
Alexsander Luís Moreto Magno Antonio Patto Ramalho Adriano Teodoro Bruzi 《Euphytica》2012,186(3):755-760
The objective of this investigation was to check if epistasis is present in Andean × Mesoamerican beans crosses using triple test cross (TTC) method. The parents of the segregating population were Carioca–MG (Mesoamerican) and BRS Radiante (Andean). In July 2005, F2 progenies (backcrossed with the parents and F1 generation) were evaluated at two locations for three characters: number of pods plant−1, number of grains plant−1 and grain weight plant−1. The presence of epistasis was detected for all yield components. In the partitioning of epistasis in additive x additive (i) and dominant x dominant (j) and dominant × additive (l) it was observed that, for the traits number of pods/plant and number of grains/plant, only epistasis of the type (j) + (l) were significant. For the trait grain mass/plant, all types of epistasis were significant. 相似文献
7.
Jean-Luc Jannink 《Euphytica》2008,161(1-2):61-69
Failures of the additive infinitesimal model continue to provide incentive to study other modes of gene action, in particular,
epistasis. Epistasis can be modeled as a QTL by genetic background interaction. Association mapping models lend themselves
to fitting such an interaction because they often include both main marker and genetic background factors. In this study,
I review a model that fits the QTL by background interaction as an added random effect in the now standard mixed model framework
of association analyses. The model is applied to four-generation pedigrees where the objective is to predict the genotypic
values of fourth-generation individuals that have not been phenotyped. In particular, I look at how well epistatic effects
are estimated under two levels of inbreeding. Interaction detection power was 8% and 65% for pedigrees of 240 randomly mated
individuals when the interaction generated 6% and 20% of the phenotypic variance, respectively. Power increased to 21% and
94% for these conditions when evaluated individuals were inbred by selfing four times. The interaction variance was estimated
in an unbiased way under both levels of inbreeding, but its mean squared error was reduced by 40% to 70% when estimated in
inbred relative to randomly mated individuals. The performance of the epistatic model was also enhanced relative to the additive
model by inbreeding. These results are promising for the application of the model to typically self-pollinating crops such
as wheat and soybean.
The U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. 相似文献
8.
Marinês Bastianel Mariângela Cristofani-Yaly Antonio Carlos de Oliveira Juliana Freitas-Astúa Antonio Augusto Franco Garcia Marcos Deon Vilela de Resende Vandeclei Rodrigues Marcos Antônio Machado 《Euphytica》2009,169(1):101-111
Leprosis, caused by citrus leprosis virus (CiLV) and transmitted by the tenuipalpid mite Brevipalpus phoenicis, is one of the most important viruses of citrus in the Americas. Sweet oranges (Citrus sinensis L. Osb.) are highly susceptible to CiLV, while mandarins (C. reticulata Blanco) and some of their hybrids have higher tolerance or resistance to this disease. The mechanisms involved in the resistance
and its inheritance are still largely unknown. To study the quantitative trait loci (QTL; quantitative trait loci) associated
with the resistance to CiLV, progeny analyses were established with 143 hybrid individuals of ‘Pêra’ sweet orange (C. sinensis L. Osb.) and ‘Murcott’ tangor (C. reticulata Blanco × C. sinensis L. Osb.) from controlled crossings. Disease assessment of the hybrid individuals was conducted by infesting the plants with
viruliferous mites in the field. The experiment consisted of a randomized completely block design with ten replicates. The
evaluated phenotypic traits were incidence and severity of the disease on leaves and branches, for a period of 3 years. The
MapQTL™ v.4.0 software was used for the identification and location of possible QTL associated with resistance to CiLV on
a genetic map obtained from 260 AFLP and 5 RAPD markers. Only consistent QTLs from different phenotypic traits and years of
evaluation, with the critical LOD scores to determine the presence or absence of each QTL calculated through the random permutation
test, were considered. A QTL was observed and had a significant effect on the phenotypic variation, ranging from 79.4 to 84%
depending on which trait (incidence or severity) was assessed. This suggests that few genes are involved in the genetic resistance
of citrus to CiLV. 相似文献
9.
10.
Kuljit Kaur Cheema Navtej S. Bains Gurjit S. Mangat Aparna Das Yogesh Vikal Darshan S. Brar Gurdev S. Khush Kuldeep Singh 《Euphytica》2008,160(3):401-409
Modern rice varieties that ushered in the green revolution brought about dramatic increase in rice production worldwide but
at the cost of genetic diversity at the farmers’ fields. The wild species germplasm can be used for broadening the genetic
base and improving productivity. Mining of alleles at productivity QTL from related wild species under simultaneous backcrossing
and evaluation, accompanied by molecular marker analysis has emerged as an effective plant breeding strategy for utilization
of wild species germplasm. In the present study, a limited backcross strategy was used to introgress QTL associated with yield
and yield components from Oryza rufipogon (acc. IRGC 105491) to cultivated rice, O. sativa cv IR64. A set of 12 BC2F6 progenies, selected from among more than 100 BC2F5 progenies were evaluated for yield and yield components. For plant height, days to 50% flowering and tillers/plant, the introgression
lines did not show any significant change compared to the recurrent parent IR64. For yield, 9 of the 12 introgression lines
showed significantly higher yield (19–38%) than the recurrent parent IR64. Four of these lines originating from a common lineage
showed higher yield due to increase in grain weight and another three also from a common lineage showed yield increase due
to increase in grain number per panicle. For analyzing the introgression at molecular level all the 12 lines were analyzed
for 259 polymorphic SSR markers. Of the total 259 SSR markers analyzed, only 18 (7.0%) showed introgression from O. rufipogon for chromosomes 1, 2, 3, 5, 6 and 11. Graphical genotypes have been prepared for each line and association between the introgression
regions and the traits that increased yield is reported. Based on marker trait association it appears that some of the QTL
are stable across the environments and genetic backgrounds and can be exploited universally. 相似文献
11.
Uttam Kumar Arun K. Joshi Maya Kumari Rajneesh Paliwal Sundeep Kumar Marion S. Röder 《Euphytica》2010,174(3):437-445
Stay green or delayed senescence is considered to play a crucial role in grain development in wheat when assimilates are limited.
We identified three QTLs for stay green on the chromosomes 1AS, 3BS and 7DS using a recombinant inbred (RI) population developed
by making crosses between the stay green parent ‘Chirya 3’ and non-stay green ‘Sonalika’. The RI lines were evaluated in natural
field conditions for 2 years in replicated trial. The QTL on chromosome 1A was identified in both the years, while the QTLs
on 3BS and 7DS were identified only in 1st and 2nd year, respectively. The QTLs explained up to 38.7% of phenotypic variation
in a final simultaneous fit. The alleles for higher stay green values derived from the stay green parent ‘Chirya 3’. The QTLs
were named as QSg.bhu-1A, QSg.bhu-3B and QSg.bhu-7D. The QTL QSg.bhu-3B and QSg.bhu-7D were placed in the 3BS9-0.57-0.78 and 7DS5-0.36-0.61 deletion bins, respectively. 相似文献
12.
Partitioning of the genotypes by environment interaction (GEI) is important in order to determine the nature of the GEI. The
objectives of this study were to assess the presence and nature of GEI for nine agronomic traits of rapeseed cultivars, and
to identify cultivars with favorable levels of stable oil production. Nine rapeseed cultivars, including seven open pollinated
and two hybrids, Hyola308 and Hyola401, were grown in ten environments under rain-fed warm areas of Iran. The GEI was significant
for all traits and was partitioned into components representing heterogeneity due to environmental index and the remainder
of the GEI. Among the all traits with a highly significant heterogeneity, the largest amount of heterogeneity removed from
the GEI was for seeds per pod and seed weight. We found GEIs for both oil content and seed yield were largely influenced by
differences in correlations among pairs of cultivars (86.8 and 71.4% of the GEI sum of squares, respectively), suggesting
that crossover GEIs (i.e., change in genotype rankings among environments) are present. The mean correlation of each cultivar
with all other cultivars ([`(r)]ii￠ \bar{r}_{{ii^{\prime}}} ) ranged from 0.53 to 0.83 for oil content and 0.86 to 0.96 for seed yield. A comparison was done of the significance of Sh-σi2 (stability variance derived from total GEI) and Sh-Si2 (adjusted stability variance derived from residual GEI) assignable to each genotype for oil content and seed and oil yield.
Based on Sh-σi2, three cultivars were unstable for oil content, whereas six cultivars were unstable for seed and oil yield. The removal of
heterogeneity revealed that one unstable cultivar for oil content and three unstable cultivars for oil yield were judged to
be stable. All cultivars with [`(r)]ii￠ \bar{r}_{{ii^{\prime } }} ≤ 0.63 were labeled unstable for oil content, whereas all with [`(r)]ii￠ \bar{r}_{{ii^{\prime } }} ≤ 0.94 were considered unstable for seed yield. The relationships between [`(r)]ii￠ \bar{r}_{{ii^{\prime } }} and Sh-σi2 were significant (P < 0.01) for oil content and seed yield. The results of rank correlation coefficients showed significant positive correlations
of Yield-Stability statistic (YSi) with oil content and oil yield. Cultivars such as Option500 and Hyola401 were identified as having stable, high levels to
seed yield and oil content. 相似文献
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Anthracnose is a serious disease affecting dry bean production especially in the cool highland areas worldwide. The objective
of this research was to study the inheritance of anthracnose resistance in market-class dry beans. A complete diallel set
of crosses was generated from nine diverse parents comprising six resistant and three susceptible to anthracnose. The F1 and F2 crosses and parents were artificially inoculated with Colletotriclum lindenumthianum Race-767 in a growth room. There was significant variation for anthracnose resistance among genotypes. General combining
ability (GCA) and specific combining ability effects were significant for resistance, indicating importance of both additive
and non-additive effects, respectively. Preponderance of GCA effects (66%) suggested that additive effects were more important
than non-additive effects (24%), which were also reflected by high heritability estimates (70%), and suggested that simple
selection or backcrossing would be useful for improving the resistance in market class varieties. The study was not conclusive
on whether epistatic gene action played a major role, but if available it might have biased the dominance gene effects. Reciprocal
effects (10%) were not significant (P > 0.05), suggesting that cytoplasmic genes did not play a major role in modifying anthracnose resistance. Parental lines
G2333, AB136, NAT002, and NAT003 showed highly negative GCA effects qualifying them as suitable parents for transferring resistance
genes to their progenies. A few major genes, 1–3, displaying partial dominance conditioned anthracnose resistance, suggesting
a possibility of using marker-assisted selection to improve anthracnose resistance in market-class dry beans. 相似文献
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18.
Chunjun Li Huilan Zhu Caiqin Zhang Feng Lin Shulin Xue Yong Cao Zhengzhi Zhang Lixia Zhang Zhengqiang Ma 《Euphytica》2008,163(2):185-191
Fusarium head blight (FHB), or scab, is a devastating wheat disease worldwide, reducing both grain yield and quality. The
percentage of Fusarium-damaged kernels (FDK) directly reflects the damage level caused by scab on wheat grains and its variation
represents the so-called type IV scab resistance in germplasm. To identify genes governing type IV resistance and investigate
its relationship with other scab resistance types, we mapped QTLs associated with percent FDK using data from three different
field evaluations of the recombination inbred line (RIL) population derived from the susceptible cultivar Nanda 2419 × the
scab-resistant cultivar Wangshuibai. Five QTLs related to percent FDK were identified in at least two different trials, for
which Wangshuibai contributed four of the resistance alleles. Most of the FDK-related QTLs, including the three with larger
effects, QFdk.nau-2B, QFdk.nau-3B and QFdk.nau-4B, mapped to intervals associated with either type IV resistance or type II resistance. Moreover, most of the major type I
and type II resistance QTLs detected previously were associated with type IV resistance, suggesting that resistance to initial
infection and disease spread play major roles in conditioning less FDK. Therefore, breeders have options to choose inoculation
methods based on their expertise and resources without risking significant loss of information when using percent FDK as the
disease index. The most useful scab resistance QTLs for breeding would be those with stable influences on FDK and/or deoxynivalenol
(DON) accumulation besides the initial infection and disease spread.
Chunjun Li and Huilan Zhu contributed equally to this work. 相似文献
19.
Shelley Jansky 《Euphytica》2011,178(2):273-281
Valuable genetic diversity in diploid wild Solanum species can be accessed through crosses to haploids (2n = 2×) of the tetraploid cultivated potato, Solanum tuberosum. Haploid-wild species hybrids segregate for the ability to tuberize in the field. In addition, they vary in male fertility,
vine size, stolon length, and tuber size. In this study, three haploids were crossed with nine diploid wild Solanum species and 27 hybrid families were evaluated in the field for two years. The proportion of male fertile hybrid clones varied
depending on the wild species parent. A large effect of the female parent was detected for vine size, stolon length, tuber
size, percent tuberization, and percent plants selected for agronomic quality. An exceptional haploid (US-W4) was identified
for the production of agronomically desirable haploid-wild species hybrids. In hybrids derived from US-W4, differences among
wild species parents were observed for agronomic quality. Superior hybrids were produced by S. berthaultii and S. microdontum. Reciprocal crosses were evaluated for a subset of families. When the wild species was used as the female parent, male fertility
was restored, but tuberization and tuber size were reduced. Careful selection of both haploid and wild species parents can
result in a large proportion of fertile, agronomically desirable hybrid offspring. 相似文献