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1.
Elaeis oleifera or ‘caiaué’, a close relative of oil palm (E. guineensis), has some agronomic traits of great interest for the oil palm genetic breeding such as slow growth, oil quality (mostly
unsaturated) and disease resistance. An analysis of a Brazilian oil palm germplasm collection was carried out using RAPD (Random
Amplified Polymorphic DNA) markers with the objective of understanding the genetic variation of ‘caiaué’ accessions collected
in the Amazon Forest in the last two decades. A sample of 175 accessions obtained along the Amazon River Basin was analyzed
and compared to 17 accessions of oil palm from Africa. Ninety-six RAPD markers were used in the analysis, of which fourteen
were shown to be specific to oil palm, while twelve were specific to ‘caiaué’. Results showed that the Brazilian ‘caiaué’
accessions studied have moderate levels of genetic diversity as compared to oil palm accessions. The data allowed the establishment
of similarity groups for ‘caiaué’ accessions, which is useful for selecting parental plants for population breeding. Cluster
analysis showed that, in general, genetic similarities are not correlated to geographical distances, but consistent with geographical
dispersal along the Amazon River network. AMOVA showed that most of the genetic variation is found within populations, as
expected for anallogamous and long-lived perennial species. The study provides important information to define strategies
for future collection expeditions, for germplasm conservation and for the use of E. oleifera in breeding programs.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
2.
Selecting high yielding upland cotton, Gossypium hirsutum L. lines with improved fiber quality is a primary breeding goal. A diverse set of ten cultivars and one breeding line were
crossed in a half diallel. Parents and F2 hybrids were grown in three environments at Mississippi State, MS. Ten agronomic and fiber traits were analyzed by a mixed
linear model approach based on the additive-dominance genetic model. Variance component, genetic effects and genetic correlations
were calculated. ‘Acala Ultima’ was a desirable general combiner for fiber length, uniformity, strength, micronaire, lint
percentage, and boll weight. ‘FiberMax 966’ was a desirable general combiner for fiber length, uniformity, strength, and all
agronomic traits. ‘Tamcot Pyramid’ and M240 were poor general combiners for both fiber and agronomic traits. ‘Coker 315’ was
a good general combiner for fiber length, uniformity, micronaire, boll weight, boll number, and yield. Heterozygous dominance
effects were associated with several crosses, which suggest their use as hybrids. 相似文献
3.
Heterosis and inbreeding depression for fruit yield has been reported for pickling cucumber (Cucumis sativus L.). However, cucumber inbreds often perform as well as hybrids, and there is little inbreeding depression. The objectives
of this study were to reexamine the amount of heterosis and inbreeding depression for fruit yield and yield components in
pickling cucumber, and to determine the relationship between yield components and yield for heterosis. Two pickling cucumber
inbreds (M 12, M 20) and inbreds from four open-pollinated monoecious cultivars (‘Addis’, ‘Clinton’, ‘Wisconsin SMR 18’, ‘Tiny
Dill’) were hybridized to form four F1 hybrids (‘Addis’ × M 20, ‘Addis’ × ‘Wis. SMR 18’, ‘Clinton’ × M 12, M 20 × ‘Tiny Dill’). F1 hybrids were then self-pollinated or backcrossed to generate F2, BC1A, and BC1B progeny. Thirty plants of each generation within each hybrid family were grown in plots 3.1 m long with four replications
in each of two seasons. Data were collected from once-over harvest for vegetative, reproductive, yield, and fruit quality
traits. Heterosis and inbreeding depression for fruit yield and yield components were not observed in three of the hybrids.
Only ‘Addis’ × ‘Wis. SMR 18’ exhibited high-parent heterosis and inbreeding depression for total, marketable, and early fruit
weight. For ‘Addis’ × ‘Wis. SMR 18’, heterosis for fruit yield was associated with a decreased correlation between percentage
of fruit set and fruit weight, an increased negative correlation between percentage of fruit set and both the number of branches
per plant and the percentage of pistillate nodes, and an increased negative correlation between the number of nodes per branch
and total fruit weight. Inbreeding depression was associated with a weakening of the strong negative correlations between
percentage of fruit set and the number of branches per plant, and between the number of nodes per branch and total fruit weight.
Those correlations were associated with high-parent heterosis and inbreeding depression only for one cross, and do not necessarily
apply to future crosses in which heterosis may be observed for yield. We did not observe the heterosis or inbreeding depression
for yield in cucumber in most of the crosses as was reported by Ghaderi & Lower (1979a; 1979c).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
Morphological and molecular characterization of melon accessions resistant to Fusarium wilts 总被引:1,自引:1,他引:0
Fusarium wilt incited by Fusarium oxysporum f. sp. melonis (F.o.m) is one of the most widespread and devastating melon diseases. While resistance to physiological races 0, 1, and 2
is relatively frequent in different botanical varieties, sources of resistance to race 1,2 are restricted to a few Far-Eastern
accessions. In this work, the results of a screening for resistance to F.o.m. race 1,2 among 32 accessions are presented.
Three Japanese accessions (‘Kogane Nashi Makuwa’, ‘C-211’, and ‘C-40’) showed the highest resistance levels, but useful levels
of resistance were also detected in one Russian ‘C-160’ and two Spanish (‘C-300’ and ‘Mollerusa-7’) accessions. These resistant
materials, together with other accessions previously described as resistant to F.o.m. races 0, 1, and/or 2 have been morphologically
and molecularly characterized. Based on cluster analysis, these accessions have been grouped according to the botanical subspecies
they belong to. Assessment of genetic diversity indicated that the resistant accessions to races 0, 1 and 2, are scattered
along the established clusters. On the other hand, high levels of resistance to the race 1,2 could be found only among accessions
belonging to Cucumis melo subsp. agrestis, nevertheless, a certain degree of resistance to this race could also be found within some accessions belonging to subsp.
melo. As far as we know, this is the first report of resistance to F.o.m race 1,2 found out from the Far-Eastern melon material.
Based on fruits characteristics, it appears that several inodurus and cantalupensis accessions could be exploited in breeding programs as resistance sources to F.o.m races 0, 1 and/or 2 for the improvement
of these melon types. The accessions with the highest levels of resistance to the race 1,2 appeared to be very distant both
molecularly and morphologically from the commercial types. Nevertheless ‘C-160’, ‘C-300’, and ‘Mollerusa-7’ classified as
var. inodorus are morphologically very similar to the Spanish commercial types and might be used as resistant sources in breeding these
melon types. 相似文献
5.
Inheritance and Correlation of Self-Compatibility and other Yield Components in the Apricot Hybrid F1 Populations 总被引:2,自引:0,他引:2
Xuesen Chen Yan Wu Meixia Chen Tianming He Jianrong Feng Qing Liang Wen Liu Honghua Yang Lijie Zhang 《Euphytica》2006,150(1-2):69-74
Summary To provide genetic basis for apricot (Prunus armeniaca Lam.) breeding, inheritance and correlation of yield components including self-compatibility, self-pollinated fruiting rate, fertile flower rate, average fruit weight and fruit number per plant were studied with 5-year-old seedlings of apricot F1 hybrids from ‘Katy’ × (‘Xinshiji’, ‘Katy’ × (‘Hongfeng’ and ‘Katy’ × (‘Taianshuixing’, respectively. Using the criteria that cultivars with self-pollinated fruiting rate ≥6% were self-compatible(SC), we found that the ratios of self-compatible (SC) to self-incompatible (SI) individuals were 27:25, 9:12 and 15:19 in the above three families, respectively, and conformed to the ratio of 1:1 segregation by χ2 test, indicating that the S-locus of ‘Katy’ was heterozygous and self-compatibility was dominant to self-incompatibility. Twenty-seven seedlings from the F1 population of ‘Katy’ × ‘Xinshiji’ were chosen for S-allele-specific PCR. As a result, four S-genotypes with the ratio of 10:6:4:7 were obtained, which was linear to the 1:1:1:1 ratio by χ2 test. Great differences in self-compatibility degree were observed among seedlings even with the same S-genotype. In the F1 populations, a very extensive segregation in self-pollinated fruiting rate, fertile flower rate and average fruit weight was observed, and average values of these traits were lower than that of mid-parent. Therefore, these traits were confirmed to be quantitative. However, significant differences were found in broad heritability (H
b
2) of following three characters: the H
b
2 of self-pollinated fruiting rate (87.1% – 91.4%) was the greatest, with the variation mainly resulted from inheritance; fertile flower rate (36.8% – 49.1%) was the least and its variation was mainly caused by environmental factors. In addition, self-pollinated fruiting rate and fertile flower rate had very significantly positive correlations with single plant yield, so both may play important roles in the determination of single plant yield. In contrast, correlation between yield and average fruit weight was not significant. 相似文献
6.
Hela Chikh-Rouhou Rafael González-Torres Ali Oumouloud José M. Alvarez 《Euphytica》2011,182(2):177-186
The resistance to Fusarium oxysporum f.sp. melonis (Fom) race 1.2 has been studied in melons, such as the Portuguese accession ‘BG-5384’ and in the Japanese ‘Shiro Uri Okayama’,
‘Kogane Nashi Makuwa’, and ‘C-211’, since a good characterization of the resistance is necessary before its introgression
into commercial varieties. These four melon accessions showed a high level of resistance to races 0, 1, and 2 of Fom, indicating that the partial resistance to the race 1.2 previously detected may not have been race specific. To determine
the mode of inheritance of the resistance to Fom race 1.2, the F1, F2, BCPR, and BCPS generations from the crosses between the four resistant accessions above and ‘Piel de Sapo’, a Fom race 1.2 susceptible melon, were developed. They were subsequently inoculated with two Fom isolates, one from the pathotype 1.2Y and the other from the pathotype 1.2W. The area under the disease progress curve was
determined for each inoculated plant, and the data were analyzed. We show that the resistance seen in these accessions is
polygenically inherited with a complex genetic control because many epistatic interactions were detected. The three epistatic
effects; additivity × additivity, dominance × dominance, and dominance × additivity are present and significant, with differing
magnitudes from one cross to the next. The relatively low heritabilities, and these epistatic effects make difficult the improvement
of the resistance, from these sources, through a standard selection procedure. 相似文献
7.
The inheritance of the resistance to Fusarium oxysporum f. sp. melonis (F.o.m.) races 0 and 2 in ‘Tortuga’, a Spanish cantalupensis accession, was studied from crosses of ‘Tortuga’ by the susceptible line ‘Piel de Sapo’ and the resistant one ‘Charentais-Fom1’
that carries the resistance gene Fom-1. The segregation patterns observed in the F2 (‘Tortuga’ × ‘Piel de Sapo’) and the backcross (‘Piel de Sapo’ × (‘Tortuga’ × ‘Piel de Sapo’) populations, suggest that resistance
of ‘Tortuga’ to races 0 and 2 of F.o.m. is conferred by two independent genes: one dominant and the other recessive. In the F2 derived from the cross between accessions
‘Tortuga’ and ‘Charentais-Fom1’, the lack of susceptible plants indicated that the two accessions are carrying the same resistance
gene (Fom-1). The analysis of 158 F2 plants (‘Tortuga’ × ‘Piel de Sapo’) with a Cleaved Amplified Polymorphic Sequence marker 618-CAPS, tightly linked to Fom-1 (0.9 cM), confirmed that ‘Tortuga’ also carries a recessive gene, that we propose to symbolize by fom-4. 相似文献
8.
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
9.
The elite and popular cultivars of Cymbopogon martinii were examined for genomic and expressed molecular diversity through RAPD, enzyme and SDS-PAGE protein polymorphisms. The
allelic score at each locus of the enzymes as well as presence and absence profiling in RAPDs, overall occurrence of band
types etc. were subjected to computation of gene diversity, expected heterozygosity, allele number per locus, and similarity
matrix. These, in turn, provide inputs to derive primary account of allelic variability, genetic bases of the cultivated germplasm,
putative need for gene/trait introgression from the wild or geographically diverse habitat etc. in elite selections. ‘PRC1’
possessed highest number of unique bands based on RAPD polymorphism. In variety ‘IW31245E’, diaphorase and glutamate oxaloacetate
transaminase isozymes generated two unique bands as dia-III
2 and got-II
4. ‘RRL(B)77’ exhibited three unique bands; one produced by esterase as allele est-II
1 and two by malic enzyme (me-III
1,3). Only one unique band was generated by malic enzyme in variety ‘Trishna’. But sofia had three unique bands, two contributed by diaphorase (dia-II
3 and dia-II
4 and one by glutamate oxaloacetate transaminase (got-II
2). SDS-PAGE analysis revealed presence of unique polypeptide fragments (97.7 kDa to 31.6 kDa) in varieties ‘IW31245E’, ‘RRL(B)77’,
‘Tripta’, ‘Trishna’, ‘PRC1’ and var. sofia, generated as a diagnostic marker. In general, molecular distinctions associated with var. motia and var. sofia have been clearly noticed in C. martinii.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
11.
D. Sharma R. C. Sharma R. Dhakal N. B. Dhami D. B. Gurung R. B. Katuwal K. B. Koirala R. C. Prasad S. N. Sah S. R. Upadhyay T. P. Tiwari G. Ortiz-Ferrara 《Euphytica》2008,164(3):689-698
The national maize improvement program in Nepal regularly receives elite maize (Zea mays L.) genotypes from CIMMYT and other countries and tests them for their performance stability in highly diverse environments.
Studies were conducted on research stations and farmers’ fields at five sites in three years to determine performance stability
of exotic maize genotypes. Replicated on-station and on-farm studies were conducted using 25 and 10 genotypes, respectively,
including a local check and an improved check (Manakamana-3), in 2004–2006. We analyzed grain yield, days to flowering, plant
and ear height, plant population, husk cover, and plant and ear aspect. Stability and genotype superiority for grain yield
was determined using genotype and genotype × environment (GGE) biplot analysis that compares among a set of genotypes with
a reference ‘ideal’ genotype, which has the highest average value of all genotypes and is absolutely stable. Several genotypes
produced significantly higher grain yield than the local check. Four genotypes (‘Across9942 × Across9944’, ‘Open Ended White
Hill Population’, ‘Population 44C10’ and ‘ZM621’), that produced significantly higher grain yield than the improved check,
also had other agronomic traits (days to flowering, plant and ear height, number of ears, resistance to leaf blight, plant
and ear aspect and husk cover tightness) equal to or better than the improved check. GGE-biplot analysis showed that Across9942 × Across9944
and ZM621 were the most superior genotypes in the on-station and on-farm trials, respectively. The findings from this study
provide new information on the stability of the maize genotypes that are also adapted to other regions of the world. Such
information could be useful for maize improvement program for the highlands in Nepal and other similar environments. 相似文献
12.
Raquel Sánchez-Pérez Encarnación Ortega Henri Duval Pedro Martínez-Gómez Federico Dicenta 《Euphytica》2007,155(3):381-391
The inheritance of 16 important agronomic traits and its relationship were studied for four years in a population of 167 almond
[P. dulcis (Mill.) D.A. Webb] seedlings obtained from a cross between the French selection ‘R1000’ (‘Tardy Nonpareil’ × ‘Tuono’) and
the Spanish cultivar ‘Desmayo Largueta’. For some traits (blooming and leafing date) descendants segregated between the value
of both progenitors, meanwhile for others the mean of the offspring was lower (bloom density, productivity and ripening date)
or higher (in-shell/kernel ratio and double kernels). As expected, kernel bitterness and self-incompatibility behaved as monogenic
traits. Some important correlations between traits were detected. The implications of the transmission and the correlation
of these traits in the breeding programmes are discussed. 相似文献
13.
14.
Pedro J. Martínez-García Fernando Mañas Prudencio López Federico Dicenta Encarnación Ortega 《Euphytica》2011,177(1):67-78
‘Marcona’ and ‘Desmayo Largueta’ are the most widely cultivated almonds in Spain, representing around 27% of the total production
and 34% of the entire almond growing surface. The excellent quality of their kernels makes them highly appreciated and demanded
worldwide. However, due to their self-incompatibility, they should be grown along with cross-compatible cultivars, whose lower
kernel quality often reduces the economic benefits of the plantation. In addition, although they are cross-compatible, are
not good candidates to share the orchard since ‘Desmayo Largueta’ usually flowers earlier than ‘Marcona’. Therefore, to optimize
orchard yield, genotypes with overlapping flowering times, cross-compatible with these cultivars and of similar fruit and
ripening characteristics are desirable. In order to find suitable pollinators of these cultivars, five ‘Marcona’ and four
‘Desmayo Largueta’-type selections from “Instituto Técnico Agronómico Provincial (ITAP) de Albacete” (Spain) were characterized
for flowering time and for self and cross-incompatibility. The results obtained showed that the nine ITAP selections were
self-incompatible, and that three and one were promising candidates as pollinators of ‘Marcona’ and ‘Desmayo Largueta’, respectively.
The S-haplotypes of two ITAP selections were characterized by cloning and sequencing their pistil S (S-RNase) and pollen S (SFB) genes. The results also showed that S
f
RNase does not have a mutated histidine in C2 region, and detected differences with other previously published sequences
for S
23
RNase and SFB
23 allele. Moreover, the sequence for almond SFB
27 allele is reported here for the first time. 相似文献
15.
Characterization of genotype by environment interactions in soybean breeding programmes of southeast Europe 总被引:1,自引:0,他引:1
Southeast Europe is Europe's major production area of soybean of maturity groups (MG) 0, I and II, but genotype by environment interaction (GEI) for soybean traits in this region is still not characterized. The objective of this study was to characterize GEI in soybean grown in Croatia for seed yield, protein and oil content. Fourteen soybean cultivars of MG 0 and I were evaluated at 15 environments. In the combined anova , genotypes, environments and GEI were significant. All three seed traits were more affected by year than by location and seed yield and protein content were more sensitive to environmental changes than oil content. Genotype by environment interaction is generally of less importance than effects of genotypes and years, especially for oil content. High‐yielding genotypes had values of regression coefficient (b) close to 1, indicating that they were not responsive to extreme environments, either positive or negative. Means and b values were not correlated for yield and negatively correlated for protein and oil content, probably because of low‐input practice in the region. The absence of recognizable differences in means, b values and principal component scores of ammi analysis between two MGs for all traits indicated that soybean cultivars of MG 0 may be recommended for growing in the region because they responded similarly to environmental changes as do full‐season genotypes of MG I. 相似文献
16.
Barley is one of the most important cereal crops grown for the livelihoods of the poor farmers of Tigray region in northern
Ethiopia. As many low input and marginal environments it has benefited less from the yield increases achieved by modern breeding.
This has been largely attributed due to genotype × environment intraction (GEI). To investigate the causes of GEI, ten barley
varieties including local checks (two farmers developed varieties, four modern varieties and three rare local varieties) were
tested over 21 environments. Participatory methods were applied to sample an adequate number of environments spanning the
regional diversity. The yielding ability and stability of the varieties was graphically depicted by GGE and PLSR biplot. There
were two major groups of environments, the central and northern highlands, the latter with less rainfall and poorer soils.
Rainfall per month and total nitrogen level were the environmental variables that differentiated these two groups. In Tigray,
rainfall in June and July were negatively correlated with yield, reflecting waterlogging problems. The different varieties
were either specifically or widely adapted across the two environments. The variety ‘Himblil’, originating in Tigray, was
the highest yielding and also most stable in the region of origin. However, it was inferior to improved varieties (Shege and
Dimtu) at high yield levels. The association of earliness with grain yield indicates that the trait can be effectively manipulated
within the existing materials. We recommend breeding for drought/water logging resistance based on selection in the target
environment as the best strategy to provide stable and high yielding varieties for Tigray. 相似文献
17.
S. Gyawali B. R. Sthapit B. Bhandari J. Bajracharya P. K. Shrestha M. P. Upadhyay D. I. Jarvis 《Euphytica》2010,176(1):59-78
Jethobudho is an aromatic rice landrace of the Pokhara valley in middle hills of Nepal. Although local consumers are willing to pay
a high price for its purchase, the landrace has a problem with quality variation. Decentralized participatory population improvement
for specific market-identified traits was conducted on “Jethobudho” populations collected from farmers’ fields in seven geographic regions of the valley in Nepal. The preferred post harvest
quality traits, field tolerance to blast and lodging, and superior post harvest quality traits of Jethobudho were established by a consumer market survey. These traits were used for screening the materials. 338 sub-populations of
Jethobudho were evaluated for yield, disease, lodging resistance, and post harvest quality traits. Significant variation was found for
culm strength, neck blast tolerance, awn characteristics, panicle length, number of grains per panicle, test grain weight
and post harvest quality traits, whereas no significant variation was found in grain yield, plant height, tiller number, maturity
period and leaf blast. Based on these identified traits and micro-milling evaluations, 183 populations were screened in on-farm
and on-station nurseries, and in succeeding years populations were further screened by plant breeders and expert farmers in
research trials, resulting in the selection of 46 populations for post harvest quality traits. Six accessions with similar
agronomic traits, field tolerance to blast and lodging, and superior post harvest quality traits, were bulked and evaluated
on-farm using participatory variety selection (PVS). The enhanced Jethobudho accessions were also evaluated for aroma using simple sequence repeat (SSR) and found to have unique aromatic genetic constitution.
Community based seed production groups were formed, linked to the Nepal District Self Seed Sufficiency Programme (DISSPRO),
and trained to produce basic seeds (truthfully labeled) of Jethobudho. The National Seed Board of Nepal released the enhanced landrace in the name of “Pokhareli Jethobudho” in 2006, as the first bulk variety of traditional high quality aromatic rice improved through participatory plant breeding
to be formally released in Nepal for general cultivation under the national seed certification scheme. Landrace improvement
is shown as an important option for supporting programmes for in situ conservation of landraces on-farm. 相似文献
18.
Ken-ichiro Yamashita Hikaru Tsukazaki Akio Kojima Takayoshi Ohara Tadayuki Wako 《Euphytica》2010,173(3):357-367
Cytoplasmic male sterility (CMS) is an indispensable trait for F1 hybrid seed production in bunching onion (Allium fistulosum L.). Expansion of the cytoplasmic diversity of F1 hybrid cultivars by introduction of various CMS resources has great potential to eliminate vulnerability to cytoplasm type-specific
diseases. This study aimed to evaluate appearance frequency of male sterile plants in several bunching onion accessions and
to identify CMS resources. In eight (‘Nogiwa Aigara’, ‘Bansei Hanegi’, ‘Amarume’, ‘Kimnung’, ‘Zhangqiu’, ‘INT/CHN/1990/GOTOU’,
‘Natsunegi’ and ‘Guangzhou’) of 135 accessions collected from Japan, China, Mongolia, Korea and Taiwan, male sterile plants
appeared with varied frequencies from 1.7% (‘Nogiwa Aigara’ and ‘Bansei Hanegi’) to 24.5% (‘Zhangqiu’). The inheritance mode
of Zhangqiu- and Guangzhou-derived male sterility was confirmed to be CMS by sib-crossings and interbreed crossings. Microscopic
examination of microsporogenesis in the CMS plants revealed that microspore protoplasm rapidly degenerated without mitotic
division after the release of microspores from tetrads. The CMS germplasm described here would be useful for the development
of “A” lines to be used in F1 hybrid seed production of bunching onion. Male fertility in ‘Nogiwa Aigara’, ‘Bansei Hanegi’, ‘Kimnung’, ‘INT/CHN/1990/GOTOU’
and ‘Natsunegi’ was verified to be controlled by a single fertility restoration locus. 相似文献
19.
A.B. Nwauzoma A. Tenkouano J.H. Crouch M. Pillay D. Vuylsteke L.A. Daniel Kalio 《Euphytica》2002,123(3):323-331
This study examined the potential of somaclonal variation for the improvement of plantain. Approximately 500 somaclones each
of ‘Agbagba’ (False Horn plantain) and ‘Bise Egome’ (French plantain) were field evaluated for their agronomic performance
and response to the black Sigatoka disease. The micropropagated populations were independently generated from a number of
suckers from each accession. Significant differences between micropropagated accessions and crop cycles were observed. Differences
between plants derived from suckers of the same accession were also expressed, indicating the chimerical nature of variation
in the traits studied. None of the plants of the micropropagated populations from ‘Bise Egome’ exhibited significantly better
disease tolerance and agronomic performance than the source accession. However,one somaclonal variant of ‘Agbagba’ (‘AO 2B2-2’)
expressed lower susceptibility to the black Sigatoka disease. Compared to ‘Agbagba’, ‘AO 2B2-2’ had a higher bunch weight,
more fruits per bunch with higher average weight, greater average length, and greater average girth. These data clearly show
that, in contrast to previous reports, it is possible to recover superior somaclonal mutants in Musa.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
S. Ceccarelli 《Euphytica》1989,40(3):197-205
Summary Breeding programs aim at improving crop production either within given macroenvironments (for example rainfed vs. irrigated) or in a wide range of growing conditions. The merit of either strategy depends on the range of testing environments and on the definition of stress environment. When environments with average yields of 3–4 t/ha are defined as stress environments, selection for stress conditions can be successfully conducted under optimum conditions. However, when the stress environment has a much lower yield potential (0.5–2.0 t/ha), direct selection in the target environment is the most efficient strategy.A review of data on widely adapted genotypes supports this conclusion.The relative magnitude of heritability in stressed and non-stressed environments is not sufficient to choose the optimum environment for selection, because phenotypic differences can be of opposite sign in different environments.The role of constitutive characters as analytical tools in breeding for yield stability in stress environments is briefly discussed. 相似文献