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1.
Approaches are needed to broaden the genetic base and improve earliness and yield potential of large-seeded beans under sustainable cropping systems. The objective of this research was to develop adapted dwarf bean populations having a commercial seed quality and yield suitable for the production in the South of Europe. The original base populations were produced from crosses between genotypes within each Mesoamerica, Nueva Granada and Peru races, and between Peru and Nueva Granada, and Mesoamerica and Nueva Granada races. Visual mass selection for plant performance was practised in the F2 and F3 generations. In the F4 and F5, single plants were harvested under two cropping systems (sole cropping and intercropping with maize). From F4, selection was based on precocity, combined with seed yield and seed commercial type. The F4:7 selected lines from each original population were compared with their parents and five checks at four environments and two cropping systems. Differences among environments, populations, parents and checks were observed for all traits. Under intercropping with maize, there was a 50% reduction in seed yield. Yield of parents and checks belonging to Andean South American races, intraracial (Nueva Granada × Nueva Granada) and interracial (Nueva Granada × Peru) populations, was higher than that of those of Middle American origin. Intraracial crosses within large-seeded Andean South American (Peru race) and Middle American gene pools (Mesoamerica race) did not produce lines yielding more than the highest yielding parent. Only two large-seeded lines selected from crosses between small- and large-seeded gene pools out-yielded the best parent and check cultivar.  相似文献   

2.
Sixteen white clover genotypes and their half-sib progenies were grown in pure stand. Each clover progeny was also grown in a mixed stand that also included three grass varieties of different species. Dry matter (DM) yield was measured over 2 years and seed yield at the second year. Competitive ability of clover families was defined as the ratio between mixed stand and pure stand for clover DM yield. Narrow-sense heritability from parent-offspring regression of pure stand data was high to moderate (h20.50) for DM yield, seed yield and most of their components. Persistence as predicted by stolon density showed negative genetic correlations with seed yield (rg= -0.70) and DM yield (r2= -0.60), whereas seed yield and DM yield tended towards a negative correlation (r2=0.45). Sizes of different vegetative or reproductive organs were generally correlated positively. Evidence was provided that the set of parent genotypes represents well the genetic variation available within the Ladino gene pool. The results highlighted the difficulty of combining relatively short-term DM yield, persistence and seed yield into a unique plant type. Differences in competitive ability emerged only in the second year, better ability being related mainly to petiole length among the traits assessed in pure stand.  相似文献   

3.
The phenotypic expression and heritability of quantitative traits vary due to genotypic differences, environmental influences and genotype by environment interactions. The objective of this study was to determine variance components and heritabilities of seed yield and its components in cowpea. Field experiments were conducted at three locations, three planting dates using ten diverse cowpea genotypes during 2004/2005. The experiments were laid out in the randomized complete block design with three replications. Results indicated significant interactions (P ≤ 0.01) among genotypes, locations and planting dates. The genotypic variance contributed ≥50% of the total phenotypic variance for the numbers of days to 50% flowering, seeds per pod, productive branches per plant and seed yield. The heritabilities of the numbers of days to 50% flowering were estimated at 50%, pods per plant (23%), days to maturity (66%), productive branches per plant (53%), 100 seed weight (11%) and seed yield (55%). The presence of considerable degree of genotypic variance among tested genotypes under various environments suggests that success in cowpea breeding could possibly be achieved through direct phenotypic selection.  相似文献   

4.
In order to investigate the agricultural potential of the genus Vicia, and identify traits associated with productivity and responsiveness to environment, 34 undomesticated Mediterranean accessions representing Section Narbonensis (V. johannis, V. narbonensis) and V. sativa were grown in five contrasting environments in northern Syria (growing season rainfall: 76–290 mm).Highly significant genotype × environment interactions were observed for all traits. For most of the components of yield, accession mean performance (productivity)was highly correlated with responsiveness across environments (r = 0.59–0.96), as defined by joint linear regressions. Thus high yielding genotypes tended to be relatively more productive than low yielding genotypes under conditions that favoured high yields. Regression analysis revealed that mean site yields were positively correlated to rainfall (r = 0.85) and its attendant effect on growing season length as measured by cumulative season temperature and phenology (r = 0.59–0.81).In order to examine yield related traits independently of taxonomy, genotypes were grouped into three categories using K-means clustering based on productivity and responsiveness of seed, hay and biological yield. Highly productive/responsive genotypes were tall with high harvest index, large seeds and low fecundity (seeds and pods per plant), whereas unproductive/unresponsive plants tended to be short, highly fecund, with small seeds and low harvest index. Principal components analysis showed that responsiveness, in terms of seed, hay and biological yields, was closely related to phenological plasticity. Thus highly productive/responsive genotypes were able to start flowering earlier than unproductive/unresponsive genotypes in early environments, but significantly later in late, higher rainfall environments. Plant growth habit was also related to yield responsiveness. In environments with little biomass production the proportion of erect plants was high in all three categories. In more favourable, high biomass environments, the proportion of erect plants in unproductive/unresponsive genotypes fell dramatically, but was unchanged among productive/responsive genotypes. We suggest that for unproductive/unresponsive genotypes competition for light is increased under optimal growth conditions. We argue that the optimal combination of fixed and responsive traits in high yielding genotypes results in a `compound interest-type' response to more favourable environments. Highly productive and responsive genotypes can capture resources more effectively than their low yielding counterparts, leading to a positive relationship between performance and responsiveness for most components of yield. Differences in productivity and responsiveness for seed, hay and biological yield reflected Vicia taxonomy, increasing in the following order from low to high: V. johannis, V. sativa, the small seeded V. narbonensis (salmonea, jordanica, affinis) V. n. var. narbonensis, and finally V. n. var.aegyptiaca. V. n. var. aegyptiaca showed the most agricultural potential, since the taxon contained all the properties of productive/responsive genotypes listed above, yielding >1 t/ha under extremely arid conditions (104 mm),and >2.5 t/ha on 290 mm rainfall, confirming its potential for dry environments. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

5.
J. Kumar  P. N. Bahl 《Euphytica》1992,60(3):197-199
Summary The efficiency of indirect selection for seed yield was compared with direct selection for yield per se in chickpea. A total of 2500 single F2 plants, derived from 50 crosses with 50 plants from each cross, were divided into five sub-populations (SP1 to SP5) of 500 plants each by including 10 plants from each of the 50 crosses. The five sub-populations were advanced upto F6 by exercising 10% selection intensity for four successive generations for number of pods per plant in SP1, number of seeds per pod in SP2, seed weight in SP3, seed yield in SP4 and random selection in SP5. The efficiency of direct and indirect selection for yield was evaluated by comparing groups of 50 F6 lines from each sub-population. SP1 and SP3 F6 lines showed higher mean grain yield than the other three methods. SP1 and SP3 were found to be almost equally efficient in developing F6 lines which were significantly superior to the check. This suggests that indirect selection for yield via pod number and seed weight is more efficient than direct selection for yield.  相似文献   

6.
Downy mildew (DM) caused by Peronospora arborescens is the most destructive disease of opium poppy which assumes considerable importance in India and other poppy growing countries. The present study was aimed at identification and evaluation of stable resistance sources of DM in opium poppy. Furthermore, genetic variability and inheritance pattern of DM resistance has also been studied which can help in making strategy for crop improvement. Evaluation of 35 selected germplasm accessions of opium poppy under glasshouse and field conditions during the three consecutive years (2004–2005 to 2006–2007) resulted in identification of two genotypes (I-14 and Pps-1) as highly resistant and stable sources for DM resistance. Genetic studies of DM resistance revealed polygenic control with the dominance of susceptibility over resistance. Significant reciprocal differences were found largely due to maternal transmission of DM resistance indicating the involvement of cytoplasmic genes in addition to nuclear control. Analysis of genetic variability and selection parameters indicated predominance of additive effects for DM resistance and other yield contributing traits. Multivariate analysis resulted in classification of 35 selected accessions into 11 different clusters revealing very high level of diversity among the genotypes. Cluster analysis suggested that hybridization program involving genotypes from cluster V (which included highly resistant genotypes Pps-1 and I-14) and cluster IX (which included highly susceptible Jawahar-16 having good economically important traits like seed yield) could be expected to give best recombinants for improvement in terms of DM resistance and high seed and straw yield in opium poppy. Analysis of selection parameters like heritability and genetic advance also suggested that simple selection methods will be effective in stabilizing resistance traits following hybridization with high yielding genotypes.  相似文献   

7.
Summary As a result of the analysis of 31 fenugreek (Trigonella foenum-graecum L.) genotypes we demonstrated that subsp. indica surpass significantly subsp. foenum-graecum in fresh weight, seed yield, nodulation ability, resistance to coot rot and the duration of the interstage and growing periods. There was no difference between the subspecies for leafiness and biochemical composition of seeds (concentrations of diosgenin and steroid glucosides, nitrogen, fat, inhibitors of tripsin and hemotripsin). The most promising genotypes (as compared with the standard cv. Nakhichevanskaya Shambala) yield 1650–1938 g/m2 of fresh weight, 98.2–116.1 g/m2 of seeds and accumulate 1.45–1.64% of diosgenin in seeds. High positive correlations (r=+0.53 ... +0.84; Po<0.01) were found between fresh weight, seed yield, plant leafiness and height. Inoculation of the cv. Nakhichevanskaya Shambala with Rhizobium meliloti strains 851 and 852 increased its fresh weight by 94.5% and 93.6% and seed yield by 83.1% and 60.5%, respectively. Significant correlations of the nodule number with the fresh weight and seed yield (r=+0.70 and +0.77; Po<0.01) allow us to assume that selection for increased symbiotic activity may be useful for improving the fenugreek productivity. The intersubspecies hybrids (four genotypes) surpass the subsp. indica (six genotypes) for the sizes of calli formed in presence of 2.4-D and kinetin. The sizes of calli formed by ten analysed genotypes in presence of BAP and kinetin (or 2.4-D) were negatively correlated with the nodule number (or fresh weight).  相似文献   

8.
Phenotypic selection under spaced planting is frequently used in forage species. This study aimed to compare the predicted efficiency of direct selection for lucerne seed or forage yield under dense planting with indirect selection based on the same traits or seed yield components evaluated under spaced planting. Sixteen genotypes randomly chosen from a representative sample of locally adapted germplasm were grown for two years as individual clones spaced at 75 cm (density =1.78 plants/m2) and in dense plots formed by one row of four clones spaced at 10 cm (density = 50 plants/m2) using a randomized complete block design with three replications. Indirect selection based on seed yield under spaced planting was just 19% less efficient than direct selection, owing to moderate genetic correlation between plant densities (rg = 0.66) and somewhat higher broad‐sense heritability under spaced planting than under dense planting. The relative efficiency of indirect selection for seed yield in density based on individual seed yield components under spaced planting ranged from modest to very low and was always below 45%. The efficiency of indirect selection for dry matter yield based on yield response under spaced planting was moderate for total yield (64%) and very low for second‐year yield (32%) relative to direct selection.  相似文献   

9.
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   

10.
Two experiments were conducted in the Rift Valley, Ethiopia (8°N and 39°E) to determine associations between eight plant traits and seed yield, and to obtain estimates of narrow sense heritability for the traits. Experiment I evaluated seven dry edible bean cultivars/lines at two locations to simulate different soil moisture stress, including, Debre Zeit(non-stress) and Dera (moderate-stress). Experiment II evaluated 25 cultivars/lines in three environments including, Melkassa early planted (non-stress), Melkassa late planted (high-stress), and Dera (moderate-stress). A randomized-complete-block design with three replicates was used in both experiments. Plant traits evaluated were seed yield, pods plant-1, seeds pod-1, 100 seed weight, root dry weight, hypocotyl diameter, plant biomass, plant height and days to flowering. Plant traits that were significantly associated with seed yield were included in a stepwise-regression model to determine which trait or combination of traits provided the best model to estimate seed yield in each environment. An analysis of variance was conducted to test main effects and interactions between plant traits and environments. Significant variation among lines occurred for seed yield and all plant traits in both experiments. Strong positive correlations were observed between plant biomass and seed yield in all environments. Seed yield and pods plant-1 were also highly associated in four of the five environments. Stepwise regression models indicated that the combination of pods plant-1 and plant biomass consistently contributed to seed yield prediction, while other traits did not. Because both plant biomass and pods plant-1 had moderate to high narrow sense heritability estimates and low GE interactions, they should be useful as indirect selection criteria to improve and stabilize seed yield in a breeding program. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

11.
Common bean (Phaseolus vulgaris L.) is the most important food legume crop in Africa and Latin America where rainfall pattern is unpredictable. The objectives were to identify better yielding common bean lines with good canning quality under drought, and to identify traits that could be used as selection criteria for evaluating drought‐tolerant genotypes. In all, 35 advanced lines were developed through single seed descent and evaluated with a standard check under drought and irrigated conditions at two locations over 2 years in Ethiopia. Grain yield (GY), pod number per m2, seed number per m2 and seed weight decreased by 56%, 47%, 49% and 14%, respectively, under drought stress. Eight genotypes had better yield with good canning quality under drought compared to the check. Moderate to high proportion of genetic effects were observed under drought conditions for GY and yield components compared to genotype × environment effects. Significant positive correlations between GY and pod harvest index (PHI) in drought suggest that PHI could be used as an indirect selection criterion for common bean improvement.  相似文献   

12.
Breeding efforts to improve grain yield, seed protein concentration and early maturity in pea (Pisum sativum L.) have proven to be difficult. The use of molecular markers will improve our understanding of the genetic factors conditioning these traits and is expected to assist in selection of superior genotypes. This study was conducted to identify genetic loci associated with grain yield, seed protein concentration and early maturity in pea. A population of 88 recombinant inbred lines (RILs) that was developed from a cross between 'Carneval' and 'MP1401' was evaluated at 13 environments across the provinces of Alberta, Manitoba and Saskatchewan, Canada in 1998, 1999 and 2000. A linkage map consisting of 193 AFLPs (amplified fragment length polymorphism), 13 RAPDs (random amplified polymorphic DNA) and one STS (sequence tagged site) marker was used to identify putative quantitative trait loci (QTL) for grain yield, seed protein concentration and early maturity. Four QTL were identified each for grain yield and days to maturity, and three QTL were identified for seed protein concentration. A multiple QTL model for each trait showed that these genomic regions accounted for 39%, 45% and 35% of the total phenotypic variation for grain yield, seed protein concentration and days to maturity, respectively. The consistency of these QTL across environments and their potential for marker-assisted selection are discussed in this report.  相似文献   

13.
A. Elgersma 《Euphytica》1990,51(2):151-161
Summary Seed yield in perennial ryegrass is low and selection criteria for high seed production are lacking. Indirect selection in spaced plants would be efficient, but spaced-plant traits need to be identified that correlate with seed yield in drilled plots. Spaced plants were studied of nine perennial ryegrass cultivars with a different seed production when grown in plots. Genotypic variation within cultivars for seed yield components and other traits was assessed in four environments in replicated clonal experiments. Extensive genotypic variation for most traits was present within each cultivar. Based on cultivar means of 25 or 50 genotypes, significant differences among cultivars were found for most traits. Cultivar-year interactions were found for most traits, but no significant cultivar-location interactions were generally found. Spaced-plant traits in general showed poor correlation to corresponding traits in drilled plots. Cultivars with contrasting seed yield in plots could not be distinguished on the basis of their spaced-plant traits and therefore no criteria for indirect selection for seed production in drilled plots could be identified in spaced plants.  相似文献   

14.
High persistence and seed yield are important targets in white clover breeding but their assessment is expensive. The efficiency of indirect selection for these traits performed on characters recorded during a medium-term dry matter (DM) yield evaluation was verified for large leaved populations in separate experiments for medium-term (three-year) and long-term (fourth and fifth year) DM yield (Trial 1) and seed yield (Trial 2). The best results were provided by stolon density observed at the end of the third cropping year for prediction of long-term yield, and by the product of number of heads times number of florets per head assessed prior to mowing in Trial 1 for prediction of seed yield in Trial 2. Indirect selection was about as efficient as direct selection in these cases. Predictions of persistence from three-year or third year DM yield, and seed yield from single seed yield components in Trial 1 were less accurate.  相似文献   

15.
Soybean (Glycine max (L.) Merrill) production is expanding into temperate and tropical environments. Yield stability studies under rhizobia inoculation were investigated in 24 soybean genotypes over two successive growing seasons at three agro‐ecological zone of Nigeria, during the 2015–2016 rainy seasons. Treatments were arranged in a split‐plot design and replicated three times. Treatments were 24 soybean genotypes and three levels of rhizobia inoculation. Results indicated that the variation of genotypes and inoculation on percentage emergence, height, number of leaves, number of branches per plant, total biomass yield, above‐ground biomass and seed yield was significant (p = .05). The effects of genotypes (G), environment (E) and G × E interactions on seed yield were also significant. Two soybean genotypes (TGx 1989‐45F and TGx 1990‐110FN) were identified as the most promising in relation to yield stability. Of the three locations, Abuja produced the least interaction effects followed by Igabi and may be most appropriate environments for large‐scale soybean production. Appropriate inoculation of soybean with inoculants (LegumeFix and or NoduMax) should be encouraged in farmer's field.  相似文献   

16.
Possibility of using interspecific hybridization to increase genetic diversity of drought tolerance in safflower (Carthamus tinctorius L.) and effectiveness of different selection methods is poorly understood. The main objectives of this study were to evaluate the effectiveness of (a) interspecific hybridization to expand genetic diversity in safflower for agronomic traits and drought tolerance in advance generations and (b) different selection methods (direct vs. indirect) for improving seed yield. Interspecific hybridizations were performed between species of C. tinctorius × C. palaestinus (TP), C. palaestinus × C. oxyacantha (PO) and C. tinctorius × C. oxyacantha (TO). Based on the field screening of genotypes in F3 generation, four groups of selected genotypes (derived from combination of direct and indirect selection under both drought and normal environments along with selection based on drought tolerance index (STI)) were evaluated in F4 and F5 generations. Indirect selection for seed yield was significantly more efficient than direct selection. Selection in stress environment resulted to more efficiency than selection in normal environment. No significant difference was observed between direct selection and selection based on STI. The result showed that TP was the best population to combine high seed yield and drought tolerance in safflower.  相似文献   

17.
Tesfaye Baye  Heiko C. Becker 《Euphytica》2005,142(1-2):119-129
Vernonia galamensis is a wild plant from the family Asteraceae which is endemic to East Africa and has the potential to become a new oil crop for industrial uses. Its seed oil is rich in vernolic acid, a fatty acid of high interest for oleochemical applications. However, a breeding program for Vernonia galamensis cultivars with high seed and oil yields requires knowledge about the genetic variability of traits that influence seed and oil production. This study was undertaken to examine phenotypic and genotypic variability, broad-sense heritability, genetic advance under selection and interrelationships of agronomic and seed quality traits. A total of 122 Vernonia accessions, 115 collected from different regions of Ethiopia and seven introduced, were grown at two locations in Ethiopia (Alemaya and Babile), in 2001/2002 and were analyzed for 20 traits including phenology, yield, yield components, and seed quality with special emphasis on fatty acid composition. The collections exhibited significant variation for all traits except for days to emergence. Genotypes and locations interacted significantly (P 0.01) for all traits. Broad-sense heritability estimates ranged from 11% (for days to emergence) up to 79% (for days to maturity). Expected genetic advance was between 1.3% (for days to emergence) and 44.8% (for seed oil yield). Genetic correlation analysis revealed that seed yield per plant is highly and positively correlated with seed weight and head number; highly significant and negative correlations (r = –0.59, –0.82, –0.85, and –0.89) were found between vernolic acid and palmitic, stearic, oleic, and linoleic acid, respectively. Highly significant positive correlations (r = 0.55, 0.44, and 0.36) were observed between vernolic acid and oil content, meal protein content and seed oil yield, respectively. Path-coefficient analysis indicated seed weight and secondary head number to be the most important components of seed yield per plant. Vernolic acid, oleic acid and linoleic acid had positive direct effects and stearic acid had a negative direct effect on oil content. The direct positive effect of oleic acid on oil content was, however, compensated by the negative indirect effects of stearic and vernolic acid resulting in a negative correlation (r = –0.60) between oleic acid and oil content. These observations will support the selection of accessions with high seed and oil yield, high meal protein contents, and high vernolic acid content.  相似文献   

18.
The definition of a suitable breeding strategy in drought-prone environments is an important task for sunflower breeders. To achieve this task, reliable information on heritability and gene effects on yield and related traits under these conditions is necessary. Thirty six sunflower hybrids were produced by factorial cross of six male-sterile and six restorer lines. Parents and their hybrids were evaluated in eight environments. Six environments consisted of two adjacent trials in the experimental area, the first under irrigation and the second under dryland conditions, during 1987, 1988 and 1992. The other environments were: one early planting trial in dryland conditions, conducted during 1987, and a winter trial planted in January during 1988. Estimates of female variance (σf) were significant for seeds per head, seed weight, head sterile center, days to blooming and oil content. Female × male interactions (σ2 fm) were significant for all characters except harvest index and index of susceptibility to drought. Estimates of narrow sense heritabilities, calculated with information from analyses combined across environments, were 0.65 for yield, 0.80 for seeds per head, 0.84 for seed weight, 0.81 for head diameter, 0.60 for sterile head center, 0.72 for oil content, 0.61 for harvest index, 0.72 for biomass, 0.94 for days to bloom, and 0.42 for drought susceptibility index. Heritability estimates for individual environments showed more variation for yield than for other traits. Estimates for heritability of canopy temperature were high (0.68–0.79). Rainfed yield was positively correlated with yield components and negatively correlated with canopy temperature and susceptibility index. It is concluded that an efficient breeding strategy for sunflower under moderate drought-stressed conditions is the simultaneous selection for seed yield in both rainfed and irrigated environments together with selection for canopy temperature and stem diameter. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
Summary Yield data were collected for soybean (Glycine max (L.) Merr.) lines in maturity groups III and IV in 14 environments from 1985 to 1989. The lines in each maturity group were subdivided into three different groups based on the mean yield over all environments, and the genotype × environment interactions were studied for each group. Yield stability of the lines was determined. Effectiveness of selection based on different types of environments was examined.Productivity level of the environment did not influence the relative ranking of the lines. Significant rank correlations occurred between mean yields in most environments and the overall mean yield, but few similarities occurred in the line rankings among individual environments. High-yielding lines contributed a significantly smaller proportion to the genotype × environment interaction than medium- and low-yielding lines.A small proportion of the lines were below or above average stability. Significant correlations occurred among stability, overall mean yield, and mean yield in high- and low-yielding environments. However, few significant correlations occurred between individual environment yields and stability in high- or low-yielding environments. Maturity groups differed in yield and stability relationships. Stability in high- and low-yielding environments did not adequately predict stability for each other.Contribution No. 93-445-J from the Kansas Agricultural Experient Station  相似文献   

20.
Seed production in perennial ryegrass, Lolium perenne L., is low. Early selection for high seed yield carried out in spaced plants would be valuable for breeders, but only if this potential is also expressed in derived progenies sown later in drilled plots. Therefore, spaced-plant traits assessed on clonal ramets of 31 genotypes in each of two perennial ryegrass varieties in four environments were related to seed production characteristics in drilled plots of open-pollinated progenies of these plants. Significant differences were found among these half-sib families for seed yield, thousand-grain weight, spring performance and earliness. The number of spikelets per ear in the maternal plants was negatively correlated with the seed yield of the progenies, explaining 17 % of the variation for seed yield in the cv. ‘Barenza’ and 14 % in the cv. ‘Wendy’. Multiple regression analyses revealed that no combinations of plant traits consistently explained a major portion of the variation for seed yield of the progenies. The results indicate that in these varieties, spaced-plant data are of limited value in predicting seed production. Direct selection for seed yield in drills of progenies in later stages of the breeding programme remains the best method for obtaining varieties with sufficient seed production.  相似文献   

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