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1.
Genetic control of alfalfa seed yield and its components 总被引：2，自引：0，他引：2
Seed yield is of little agronomic importance in alfalfa (lucerne) but is critical in the marketing of varieties. In order to develop breeding criteria, the quantitative genetics of seed yield components must be studied. The objective of this study was (1) to evaluate combining ability for seed yield and its components and (2) to estimate the genetic control of these same characters. A 7 × 7 diallel mating design, including reciprocals, among parents from different varieties, and a 7 × 7 factorial design within the ‘Flamande’ population were evaluated. In the diallel design, where the progenies were evaluated over two growing seasons, a high genotype effect was found for seed yield and its components while genotype × year interaction was only significant for seed yield per plant. General combining ability (GCA) effects explained most of the variation due to genotype effect. Specific combining ability (SCA) and reciprocal effects were only significant for seed yield per plant. ‘Europe‐1’, ‘Rival‐5’ and ‘Medalfa‐7’ were the most promising parents, conferring the highest GCA for most of the characters evaluated, especially for seed weight per inflorescence. In the factorial design, seed weight per pod was the only character for which the year effect was not significant. Male and female effects were significant for all characters and these effects were larger than the male × female interaction variance for all the characters. These results were stable over the 2 years for most characters. Additive variance was larger than dominance variance, for all traits. This resulted in high narrow‐sense heritabilities, especially for seed yield per plant, seed weight per inflorescence and number of seeds per pod. Seed weight per inflorescence and number of seeds per inflorescence were highly correlated with seed yield per plant among the full‐sib (FS) families, in both experiments. Increase in seed yield potential in alfalfa could be achieved by the use of seed weight per inflorescence as a selection criterion. 相似文献
2.
Summary The magnitude of genetic expression and associations among traits are important for the prediction of response to selection in diverse environments and provide the basis for planning and evaluating breeding programs. In this regard, a cross classification mating design was used to produce hybrid sorghum populations, which were evaluated in a randomized completed block design with three replications at four environments in Northern Cameroon. Data on grain yield, days to anthesis, plant height, inflorescence length, threshing percentage and seed mass were collected and subjected to statistical genetic analyses. Significant genotype × environment interaction effects were observed for all traits. Genetic variance was essentially attributed to additive gene effects, with dominance variance for grain yield being negligible. However, the reverse was observed for threshability. Genetic variance components were much higher for plant height and grain yield than for days to anthesis, seed mass and threshability. Heritability estimates for plant height and inflorescence length were high (77 and 54 percent respectively) while the estimates for grain yield and threshability were low (14 and 5 percent respectively). Grain yield had positive genotypic correlation with most of the traits. Days to anthesis were negatively correlated with vegetative and reproductive traits. These results suggest that improvement of days to anthesis, plant height, and inflorescence length should be faster because of higher heritabilities and greater phenotypic variation. However, selection for earliness and reduced plant height would not be possible without hampering grain yield. Selecting for yield primary components namely inflorescence length and seed weight would be effective for increasing production. In addition, optimizing agronomic practices and improved experimental design would increase the selection efficiencies. 相似文献
3.
Identification of Genes Controlling Pod Length in Spring Rapeseed, Brassica napus L., and their Utilization for Yield Improvement 总被引：6，自引：0，他引：6
Experiments were undertaken to determine the inheritance of pod length in a cross with spring rapesecd, Brassica napus, and to assess the value of pod length as a criterion of selection for high seed yield. Analyses of patterns of variation in F2; and backcross populations derived from a cross between a short-pod line TB42 and long-pod line CA553 indicated that much of the variation in pod length could be attributed to two major genes interacting in a complementary manner. Short-pods were produced when cither one or both genes were homozygous for the recessive allele. Analyses of F3 progenies of selected F2 and inbred-backcross lines derived from the same cross supported the two-gene hypothesis but also indicated that the effects of the major genes on pod length were possibly modified by genes of minor effect. Field testing of families derived from random intermating between F2, plants of the TB42 × CA553 cross showed that number of pods per plant varied independently of pod length, but seed weight per pod tended to increase with increasing pod length. As a result, families with the longest pods generally had significantly higher yields than those with short pods. It was concluded that yield improvement in B. napus could be achieved through introgression of long-pod genes into cultivars with an appropriate genetic background to ensure that selection for the long-pod character would be accompanied by an increase in seed weight per pod with little or no reduction in number of pods per plant. 相似文献
4.
Prity Sundaram Srinivasan Samineni Sobhan B. Sajja S. P. Singh R. N. Sharma Pooran M. Gaur 《Euphytica》2018,214(4):63
Seed size, determined by 100-seed weight, is an important yield component and trade value trait in kabuli chickpea. In the present investigation, the small seeded kabuli genotype ICC 16644 was crossed with four genotypes (JGK 2, KAK 2, KRIPA and ICC 17109) and F1, F2 and F3 populations were developed to study the gene action involved in seed size and other yield attributing traits. Scaling test and joint scaling test revealed the presence of epistasis for days to first flower, days to maturity, plant height, number of pods per plant, number of seeds per plant, number of seeds per pod, biological yield per plant, grain yield per plant and 100-seed weight. Additive, additive?×?additive and dominance?×?dominance effects were found to govern days to first flower. Days to maturity and plant height were under the control of both the main as well as interaction effects. Number of seeds per pod was predominantly under the control of additive and additive?×?additive effects. For grain yield per plant, additive and dominance?×?dominance effects were significant in the cross ICC 16644?×?KAK 2, whereas, additive?×?additive effects were important in the cross ICC 16644?×?JGK 2. Additive, dominance and epistatic effects influenced seed size. The study emphasized the existence of duplicate epistasis for most of the traits. To explore both additive and non-additive gene actions for phenological traits and yield traits, selection in later generations would be more effective. 相似文献
5.
为了研究江淮地区燕麦籽粒生产的影响因素,选取了13个皮燕麦种质和7个裸燕麦种质,对其12个主要农艺性状和籽粒产量进行了相关性分析和通径分析。结果表明,12个农艺性状与皮燕麦籽粒产量的相关性大小依次为分蘖数>茎叶比>株高>茎粗>千粒重>穗长>旗叶宽>轮层数>小花数>穗鲜重>旗叶长>小穗数;对逐步回归分析筛选出的6个农艺性状和皮燕麦籽粒产量做通径分析,其直接效应依次为茎粗>分蘖数>茎叶比>穗长>株高>千粒重,株高和千粒重为负效应。农艺性状与裸燕麦籽粒产量相关性依次为小花数>旗叶长>小穗数>茎粗>穗长>分蘖数>穗鲜重>株高>轮层数>旗叶宽>茎叶比>千粒重;进行通径分析后,直接效应大小为穗鲜重>穗长>茎粗>小穗数>小花数>旗叶长>分蘖数,旗叶长和分蘖数为负效应。综合考虑,皮燕麦籽粒丰产的关键在于增加单株分蘖数;裸燕麦的生产过程中则要选择小穗性状优良、小花数适中的品种。 相似文献
6.
Summary Heritabilities and responses to selection for cut flower yield were estimated for a population of gerbera. Broad-sense heritabilities averaged 42 percent, but may be as high as 66 percent. Narrow sense heritabilities averaged 68 percent when based on half-sib families, and averaged 60 percent when based on parent-offspring regression. These results suggest that most genetic variance for flower yield is additive.However, estimates of realized heritability averaged only 16 percent and inbreeding depression was estimated to be at least 38 percent, suggesting a major role for non-additive genetic variance. Nonetheless, selection for cut flower yield is expected to be successful. 相似文献
7.
8.
E. E. Mahdy 《Plant Breeding》1988,101(3):245-249
The breeding materials used in this study were the F3, F4 and F5-generations of the cross between Giza 158 × Sonora 64 (Triticum aestivum L.). The objective of this study was to compare the relative merits of Smith-Hazel, desired gain selection indices, independent culling levels and single trait selection in improving grain yield, heading date and several agronomic traits. Highly significant differences among F3 families and a satisfactory genotypic coefficient of variability were obtained for all the traits studied. The genotypic correlations were high between yield and each of spike weight, kernels/spike and spikes; plant, intermediate with 1000 kernel weight and very low with heading date, plant height and spike1 length-After two cycles of selection, the results of the gains realized indicated that the most effective method for improving yield was the Smith-Hazel index (SH7) of seven traits followed by the desired gain index of seven traits (DG7), SH5, independent culling levels, DG5 and direct selection (or grain yield/plant. Direct selection for heading date, plant height and spike length was the best method for improving these traits, but undesirable correlated responses in the other traits were obtained. 相似文献
9.
Summary Fourteen lines of linseed (Linum usitatissimum L.) were evaluated for general and specific combining ability through line × tester cross analysis using five diverse testers in two different environments. Seventy F1's and nineteen parental genotypes were raised in completely randomized block design with two replications with respect to yield and yield related traits. Considerable genetic variation was observed for all the traits studied. The additive as well as non-additive gene effects played significant role in the inheritance of yield and related traits with preponderance of non-additive gene effects for all the traits studied. Higher proportion of general combining ability × environment interaction variance as compared to specific combining ability × environment estimates was recorded. Additive genetic variances were more sensitive than non-additive genetic variances to the changing environment. Low estimates of heritability (narrow sense) for primary branches per plant, capsules per plant, seeds per capsule, seed yield per plant, harvest index and oil content and medium heritability for days to 50% flowering, days to maturity, plant height and 1000-seed weight was observed. Among the female parents LCK-9816, Parvati, Himalini, KL-168 were good general combiners for yield and related traits along with oil content, whereas among male parents, Surbhi and KL-224 were good general combiners for yield related traits and oil content but KL-221 was good general combiner for seed yield and related traits. 相似文献
10.
矮秆超大穗小麦亲本与多抗丰产小麦主要农艺性状的配合力评价及遗传分析 总被引：1，自引：1，他引：0
为了进一步挖掘矮秆超大穗小麦亲本在遗传育种中的应用潜力,为小麦高产、超高产育种选择优良亲本和最优杂交组合提供理论依据,选用5个矮秆超大穗小麦品种（系）作为父本,8个多抗丰产小麦品种（系）作为母本,按NCII遗传交配设计,采用8×5不完全双列杂交法,配制了40个杂交组合,对小麦亲本及杂种F1的株高、主穗长、单株穗数、结实小穗数、主穗粒数、主穗产量、单株产量、千粒重8个性状进行了考察,并在基因型方差分析显著的基础上进行了配合力评价及遗传力分析。结果表明：父本中A1、A3、A4是综合性状优良的亲本,其多数性状的一般配合力均较高,特别是穗长、主穗粒数、结实小穗数、主穗产量、单株产量的一般配合力高,而株高的一般配合力效应值较低,是很理想的矮秆超大穗多粒亲本材料。母本中B5、B6单株穗数一般配合力较高,株高的一般配合力效应值较低,可作小麦高产杂交育种的矮秆多穗型亲本使用。结合特殊配合力效应分析：组合B5×A3单株穗数、主穗产量、单株产量、千粒重特殊配合力效应最高,株高特殊配合力效应较低,可作为的矮秆、多穗、粒重高且高产的重点杂交组合。B2×A4主穗长、单株产量、单株穗数特殊配合力效应都较高,而株高特殊配合力效应低,可作为矮秆大穗高产的重点杂交组合。遗传力分析表明：单株产量、千粒重、主穗长、主穗产量皆在70%以上,表明这4个性状的广义遗传力较大,受环境影响较小,而狭义遗传力的分析除主穗长、主穗粒数、主穗产量、株高大于50%,其余4个性状均低于50%,说明受环境影响大,不宜早期选择,应该适当推迟选择的代数。 相似文献
11.
Information on the genetic variability of seed yield and yield components is limited and no information is available on correlations
among seed yield and yield components and direct and indirect effects of the yield components on seed yield in switchgrass,
Panicum
virgatum L. Accordingly, we conducted replicated experiments at Chickasha and Perkins, OK, in 1998 involving 11 lowland type switchgrass
populations to assess genetic variation for seed yield and yield components, quantify interrelationships among them, and determine
direct and indirect effects of yield components on seed yield through path coefficient analysis to identify traits for indirect
selection of seed yield. Significant (P ≤ 0.01) variation existed among the 11 populations over locations for percent seed set and 100-seed weight. Seed yield/plant
and the seed yield components panicle number/plant, spikelet number/panicle, and seed number/panicle had significant (P ≤ 0.05) population × location interactions, indicating substantial environmental influence on these traits for these populations.
Accordingly, data for these traits were analyzed separately for each location revealing significant (P ≤ 0.01) differences among populations at both locations for each of these traits. Phenotypic correlation between seed yield/plant
and seed number/panicle was positive (r = 0.76** at Chickasha and r = 0.72** at Perkins). Path coefficient analyses revealed that seed number/panicle had the highest positive direct effect
on seed yield at both locations. Ample genetic variability was present among the switchgrass populations studied to allow
breeding improvement of seed yield. Selection for increased seed number/panicle would be the most effective means of indirectly
selecting for higher seed yield within this germplasm. Correlation and path coefficient analyses among biomass yield, seed
yield, and harvest index indicated that, at least within the switchgrass germplasm studied, it would be possible to breed
switchgrass cultivars with enhanced biomass yielding ability and sufficient seed production capability for their commercial
propagation. 相似文献
12.
L. A. Foga?a R. A. Oliveira F. L. Cuquel J. C. B. Filho W. A. Vendrame A. F. C. Tombolato 《Euphytica》2012,184(3):301-310
Daylily (Hemerocallis × hybrida Hort.) is a popular ornamental plant and hybrid cultivars are frequently selected for medium size, large number of flowers
per stem, and flower color diversity. However, daylily selection is limited due to the lack of information on genetic parameters
and their correlation to phenotypic characteristics. This study aimed at estimating genetic parameters and genetic correlations
among full sib families of 13 daylily cultivars using REML/BLUP (restricted maximum likelihood/best linear unbiased prediction)
and to select families with high genotypic values for plant height and number of floral buds per stem. Crosses were performed
among those cultivars and 24 families were obtained. In the third year, plant height, leaf length and width, stem number,
number of floral buds per stem, and number of floral buds per plant were evaluated. The estimates of average heritability
of families were superior to the estimates of restrict individual heritability for all characters evaluated. High heritability
estimates were obtained for plant height, leaf length, leaf width, stem number, and number of floral buds per plant. Selected
families showed genetic gain of 19.80% for plant height, 32.48% for stem number, and 38.64% for number of floral buds per
plant. 相似文献
13.
Cecilia Martínez Susana Manzano Zoraida Megías Dolores Garrido Belén Picó Manuel Jamilena 《Euphytica》2014,199(3):349-362
Cytoplasmic genic male sterility system based hybrids were synthesized by line × tester design and evaluated with check GTH 1 in RBD at Sardarkrushinagar, Jagudan and Khedbrahma during kharif 2007. Analysis of variance in individual and across environments revealed significant differences among genotypes and existence of overall heterosis for seed yield per plant and other thirteen traits. The top ranking on the basis of standard heterosis were CMSGT087A × GTR0525 (116.40 %) followed by CMSGT087A × AGTR0534 (108.93 %), CMSGT0307A × AGTR0538 (99.21 %) and CMSGT 0301A × AGTR 0534 (95.51 %) for seed yield per plant and for one or two of its contributing traits. Combining ability analysis revealed presence of both additive and non-additive gene effects. The specific combining ability variance was found more compaired to general combining ability variance for all the characters under studied. This favored a hybrid breeding programme. In stability analysis, linear portion was considerably high for all the traits except for days to flower and pod length. The best stable hybrids for seed yield per plant over environments were CMSGT 308A × AGTR 0534, CMSGT 307A × AGTR 0543, CMSGT 0308A × AGTR 0536 and CMSGT 0311A × GTR 0525 and also recorded stability in any one or more of its contributing traits viz. pods per plant, branches per plant, seed per pod, pod length and test weight. Top ranking hybrids had high mean performance, high heterosis and desirable sca effects and stability for seed yield per plant. Therefore, these hybrids could be valuable for commercial exploitation. 相似文献
14.
José Manoel Colombari Filho Marcos Deon Vilela de Resende Orlando Peixoto de Morais Adriano Pereira de Castro Élcio Perpétuo Guimarães José Almeida Pereira Marley Marico Utumi Flávio Breseghello 《Euphytica》2013,190(1):117-129
A durum wheat recombinant inbred line population developed from PDW 233 × Bhalegaon 4 cross was analyzed in five environments to understand the genetic network responsible for test weight (TW), thousand kernel weight (TKW), grain yield (YLD), spike length (SL), spikelets per spike (SPS), kernels per spike (KER) and kernel weight per spike (KWS). Genotype, environment and their interactions were main sources of variance for all the traits. TW and TKW were influenced by 11 main effect QTL and 6 digenic epistatic interactions detected on chromosomes 2A, 2B, 4B and 7A. Grain yield was influenced by three epistatic interactions and five main effect QTL, of which two on chromosome 2A were most consistent. A major QTL for spike length was observed on chromosome 3B. QTL for spike characters were distributed over 9 chromosomes. All the traits showed significant influence of digenic epistasis (QQ) and, to a certain extent, QTL × environment interactions (QQE). Therefore, while breeding for complex traits like kernel characters and grain yield components, these interactions should also be considered important. The consistent QTL on chromosome 2A between the marker interval Xgwm71.2–Xubc835.4 with pleiotropic effect on TW and TKW, may be utilized in early generation selection to improve TW and TKW and thereby the milling potential of the durum wheat. 相似文献
15.
Variation in seed production and its components was investigated between and within four cultivars of the pasture grass Setaria
sphacelata, in two experiments over two years, as a basis for future cultivar improvement. The study sought to determine the
basis for the considerable differences in seed production of the four cultivars Nandi, Narok, Solander and Kazungula, to determine
the extent of genetic variation in the four cultivars in attributes which contribute to seed yield, and to investigate genotypic
consistency in seed production over years and seasons. Each experiment comprised 50 genotypes of each cultivar. In the first
experiment, plants were harvested a set number of days after median flowering date whereas in the second experiment, which
was unreplicated, each genotype was harvested a set number of days after it had flowered. In the first experiment, seed yields
were generally highest for Kazungula, lowest for Narok and intermediate for Nandi and Solander. All measured attributes contributing
to seed yield exhibited a high order of variation between and within cultivars, but the basis for the large difference in
seed yield per plant between cultivars was tiller fertility rather that total tiller number. Averaged over the four harvests,
there was a six fold to > 100–fold intra-cultivar genetic range in seed production, associated with differences in tiller
fertility, which were associated with differences in date of first flowering. Broad sense heritability for seed yield averaged
0.68 for the four cultivars and showed little change over the four harvests. Genotypes which produced high seed yields in
summer were also more productive of seed in autumn and the 0ore productive genotypes in the first year were also more productive
in the second year. Cultivars differed in the relative importance of factors which contributed to the high seed yield of high-yielding
genotypes. In the second experiment, genotypes with a high seed yield also generally had the highest tiller fertility, even
though all genotypes were harvested the same number of days after first flowering. Within-cultivar correlations in seed yield
between the two experiments were generally significant and the elite 20% of genotypes from this experiment had 1.2–2.9 times
the seed yield of the same genotypes with a very different harvesting regime in the first experiment. It is concluded that
opportunities exist in all four cultivars for improvement in seed production and that the selection criterion offering the
best opportunity for advance would be fertile tiller number. In Narok, Solander and Nandi, this would result in increased
tiller fertility, whereas in Kazungula, it would result in an increase in total tiller number.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
Phenotypic and genotypic variation in seed production traits within a full-sib family of meadow fescue 总被引：2，自引：0，他引：2
Phenotypic and genotypic variation for seed yield and associated traits (heading date, plant height, number of fertile tillers, 1000‐seed weight, panicle length, seed weight per panicle, fertility, flag‐leaf length and flag‐leaf width) were studied in a full‐sib family of meadow fescue using replicated clonal trials at two locations in Norway. Genotypic variances were highly significant for all traits and genotype × location interactions were significant for heading date, number of fertile tillers and seed yield. Seed yield and other seed component traits exhibited the largest genotypic variations. Heading date showed large genotype × location interaction, probably because of the very diverse origin of the two parents of the full‐sib family. Path coefficient analysis showed that panicle fertility, measured as seed weight per unit length of panicles, was by far the most important component trait contributing to seed yield, followed by the number of fertile tillers, plant height and flag‐leaf width. Flag‐leaf width and plant height had sizeable indirect effects on seed yield via panicle fertility. This is the first time that the importance of the size of the flag leaf for seed yield in herbage grasses has been demonstrated. 相似文献
17.
Two generations of recurrent phenotypic selection for seed yield per plant under controlled pollination were carried out to
combine improved seed yield with improved forage grass performance in perennial ryegrass (Lolium perenne L.). Selected and unselected varieties (AberDartand AberElan respectively) and control varieties were grown for seed in pots
in a glasshouse experiment and in two field plot experiments over 5 harvest years. Seed yield components and seed yield were
measured. Significant improvements in seed yield of the selected AberDart over the unselected AberElan were observed both
in individual plants grown in the glasshouse and in field plots. Detailed observations of the individual components of seed
yield showed that the increased seed yield of AberDart can be attributed to a higher proportion of ovules forming seeds (%
seedset), greater seed number per tiller and more reproductive tillers per plant. This improvement in seed yield of AberDart
was also observed when it was grown in field plots with AberElan, experimental selection lines and commercial varieties. AberDart
produced more seeds per tiller than the other commercial varieties and selection lines studied. The implication of this approach
for the breeding of perennial ryegrass varieties that combine good agronomic performance and acceptable seed yields is discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
糯高粱新选不育系的配合力及遗传力分析 总被引：2，自引：1，他引：1
为了筛选出遗传力和配合力表现优良的糯高粱不育系亲本,提高杂交育种效率,为杂交糯高粱育种选择优良亲本和配置强优势组合提供参考。选用3个糯高粱新选不育系、3个恢复系,按不完全双列杂交法组配9个杂交组合,采用DPS数据处理软件对株高、穗长、穗粒重、生育期、千粒重、产量6个主要农艺性状进行配合力及遗传效应的分析。结果表明,不育系11476A2在株高、穗长和生育期的一般配合力均有较高的优势,相对效应值分别为2.5572、2.4284和0.6792;不育系11494A2的穗粒重和产量一般配合力最高,相对效应值为5.7165和4.8505。这些亲本系在育种和生产上具有很高的利用价值。加性方差与基因型方差的比值依次顺序为株高>穗粒重>千粒重>产量>穗长>生育期。从产量性状分析看,11476A2×L17可能是一个较理想的组合模式。 相似文献
19.
Within-boll yield components are the most basic contributors to lint and seed yield of cotton (Gossypium hirsutum L.), which is a major source of natural fiber and edible oil throughout the world. Little information is available on genetic effects and heterosis of these traits in cotton. Three cotton cultivars and six breeding lines differing in within-boll yield components were used for this study. Parents and their F1 progeny with reciprocals from a 3×6 factorial mating design were grown at Jiangxi Agricultural University experimental farm in 2008 and 2009. Seven within-boll yield components and two boll bur characters were analyzed under an additive-dominance genetic model with genotype and environment interaction. Additive effects were significant for all traits and dominance effects were significant for all traits except seed mass per seed. Genetic variances for lint mass per seed, SM/S and boll bur weight were primarily additive variances ranging from 39.6 to 58.9 %. Lint mass per boll and seed number per boll variances were primarily due to dominance genetic effects ranging from 36.4 to 48.8 %. Dominance and additive effects were equally important for boll weight, seed mass per boll and boll bur percentage. Additive and additive × environment effects were more important than other effects for lint percentage. A802-1 had the best mean performance and additive effects increasing BW, SM/B, S/B and SM/S, but reduced LP and LM/S. A9-1 and Lu40534 had additive effects associated with increasing LP. The two crosses A9-1×Lu40534 and Tezsh×33B were detected with favorable heterozygous dominant effects and heterosis over best parent for BW, LP, LM/B, SM/B and S/B. Favorable genotypic and phenotypic correlations were identified between within-boll lint yield components (LM/B, LM/S) and within-boll seed yield components (SM/B, S/B, SM/S). These results indicate that simultaneous genetic improvement of multiple within-boll yield components can be expected in breeding populations derived from these cotton cultivars and breeding lines. 相似文献
20.
Tetraploid clones of potato with a superior efficiency in producing androgenetic plants (4 × EAPP-clones) have been obtained by culturing in vitro anthers of 2 × EAPP-clones. The latter were isolated by three cycles of recurrent selection from diploid breeding material (UHRIG 1985 a). In this paper we report on the capacity of 4 × EAPP-clones, when crossed to in vitro unresponsive 4 × genotypes, to transmit to their F1 their androgenetic potential, Five 4 ×× 4 × F1 crosses were considered, which produced on average 35 embryoids per flower – a value higher than that of nonresponsive 4 × genotypes (no embryoids obtained), but-also significantly better than the value found for 4× EAPP-clones (9.8 embryoids per flower). The hybrid families behaved differently from each other, with one producing up to 63 embryoids per flower. A range of per plant values was, moreover, found, revealing the existence of a large variability among sister plants belonging to the same F1 cross. The presented data indicate a rather simple inheritance of dominant genetic factors acting in favor ot androgenesis. They also suggest that the utilized 4× EAPP-clones were possibly heterozygous for such genes. Data are also reported on the ploidy level of anther plants obtained from 4× and 2× EAPP-clones. In this respect 2× EAPP-clones show the interesting capacity of generating, via anther culture, a consistent fraction of tetraploid plants (13,7 %). Based on the findings reported in this paper we propose, for tetraploid S. tuherosum L., a cyclic breeding procedure making use of anther culture and where ploidy level alternates, within a cycle, between 2× and 4×. 相似文献