Changes in adaptation in a Swedish and an Italian lucerne variety when grown for seed without isolation

Seed of two lucerne varieties, Tuna from Sweden and Nostrale (common) from Italy, multiplied in isolated stand and in the vicinity of each other, was tested in field trials at Perugia (Italy) and at Uppsala (Sweden). In both places distinct differences between the intercrossed populations Tuna (× Nostrale) and Nostrale (× Tuna) were demonstrated. The decrease in winterhardiness as compared with Tuna was very pronounced in the trial at Uppsala. It is concluded that the influence of volunteer lucerne plants in a field or in the vicinity of a seed field is economically very important when seed of a North European variety is produced outside the area of adaptation.

---

Samenvatting Zaad van twee lucernerassen, Tuna uit Zweden en Nostrale uit Italië, afkomstig van geïsoleerde en van naast elkaar gezaaide velden, werd gebruikt voor veldproeven te Perugia (Italië) en te Uppsala (Zweden). Op beide plaatsen konden duidelijke verschillen tussen de populaties Tuna (x Nostrale) en Nostrale (x Tuna) worden vastgesteld.Opvallend was de achteruitgang in winterhardheid van het in Italië, in de nabijheid van het ras Nostrale, vermeerderde Zweedse ras Tuna.Geconcludeerd wordt dat bij de vermeerdering van Noord-Europese lucernerassen in andere landen (buiten het gebied, waaraan zij zijn aangepast) spontane kruisbestuiving met andere rassen of opslag-planten voorkomen dient te worden.

     

Swedish land-races of red clover

The collection of Swedish local red clover strains, owned by the Swedish Seed Growers' Association, may serve as an attempt to organize a gene bank for land-races of red clover in Northern Europe. From all 43 strains seed is available and it is hoped that seed of satisfactory germination capacity can be kept available for the future. It may be obtained for research purposes in samples of not larger than 100 grams from the Swedish Seed Association, Uppsala 1, Sweden.     

Spaced-plant traits related to seed yield in plots of perennial ryegrass (Lolium perenne L.)

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.     

Improved seed yield in perennial ryegrass (Lolium perenne L.) from two generations of phenotypic selection

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.     

Selection for Seed Yield in Lolium perenne L.*

Components of seed yield were estimated for each set of 100 plants derived from six varieties of Lolium perenne. Significant differences between the varieties were found for all components of seed yield, but the range was broader within each variety. An indirect selection of seed yield using the character seeds per spike produced a selection response similar to that obtained by direct selection on high seed yield per plant. A direct and indirect selection of characters estimated in small, drilled plots of topcross off-springs (F₁) was less successful than the selection based on the single plants. Spearman rank correlation coefficients between the single plants and their offsprings did not show significant agreement for seed yield. But altogether the results indicated that the increase of seed yield/area was about 6 % when 10 % of the best plants were selected.     

Relationship between Seed Characters, Plant Growth and Yield Parameters of Phaseolus vulgaris

Legumes are an important component of the dietary pattern of the developing world. Thus optimal yields are a vital factor in agricultural production in these countries. Seed characters affect plant growth and yields of grain legumes. Due to the lack of similar studies in Phaseolus vulgaris (Frenchbeans), a study was carried out to determine the effect of seed characters on the growth cycle of frenchbean plants. Seed size was primarily determined by the size and weight of cotyledons and seed coat, as embryo size was similar in all seed classes. Seed size had no effect on seed viability, although larger seeds germinated earlier. There was a positive relationship between seed size and plant growth characters. Larger seeds developed plants with better growth and yield component parameters, resulting in higher yields. The importance of determining seed size in frenchbeans is presented.     

Seed Shattering of Cañahua (Chenopodium pallidicaule Aellen)

Cañahua (Chenopodium pallidicaule Aellen) is a semi‐domesticated relative of quinoa (Chenopodium quinoa Willd.) with high nutritious quality. It is tolerant to frost, drought, saline soils and pests. One seed yield limitation is seed loss during the maturity stages. Two greenhouse experiments in Denmark and field experiments in Bolivia were carried out to determine seed shattering in landraces and cultivars with different growth habits. 15–21 % of the seed shattering in the fields took place whilst the plants still were flowering and 25–35 % during physiological maturity. Seed shattering varied between locations on the Bolivian Altiplano. Cañahua types with the semi‐prostrate growth (‘lasta’) had the highest seed shattering rate in the greenhouse experiments. The Umacutama landrace had lower seed shattering (1 %) than the cultivar Kullaca (7.2 %) both of the ‘lasta’ type. Under field conditions, the cultivar Illimani with the erect growth (‘saihua’) had the highest seed shattering rate (6.4–33.7 %) at both locations and at four different sowing dates. The Umacutama had the lowest rate (0.5–1.5 %). There were no significant differences between plants of the ‘lasta’ and the ‘saihua’ types. The landrace had significantly less seed loss than the cultivars. However, in the greenhouse, the landrace yield was approximately 25 % lower than the yields of the cultivars. In general, cañahua cultivars had higher yield compared to landraces, but also a higher seed shattering rate. Landraces may be used in breeding programmes to develop high‐yielding cultivars with reduced seed shattering.     

The Relationship Between Progeny Seed Yield in Drilled Plots and Maternal Spaced-Plant Traits in Perennial Ryegrass (Lolium perenne L.)

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.     

Wild wheat adaptation in different soil ecosystems as expressed in the mineral concentration of the seeds

Wild emmer wheat, Triticum dicoccoides, grows naturally in several habitats in northern Israel. The assumption that a genotype is better adapted to the `native' soil from which it was collected than to other soils, was tested. Each of nine T. dicoccoides accessions from nine different habitats and three wheat cultivars was sown in soils taken from all habitats, and grown in a greenhouse over 3 years. To enhance the biological nutrition absorption forces from the soil, three common wheat cultivars were added to the wild genotypes. No interaction in grain yield between wild wheat genotype and soil type was found within experiments. Soil type was the main factor that affected development and yield. Seed nutrient ability (SNA) of each soil was defined as the mineral element content in the seeds, averaged over all genotypes. Multiple regression analysis revealed diversity between the SNA related to growth and yield of the genotypes. Total seed yield per plant of each accession was related to several SNAs, and mainly to S and K, R² = 0.5–0.85. The spikelet number per spike was determined by N and Na in five accessions and by Ca in the other four (R² = 0.39–0.93).Heading date was affected mainly by the genotype, and the soil effect exhibited Fe and P dependence. A genotype-habitat adaptation exhibited by yield components was related to yield quality rather than to yield quantity. When a mineral nutrient is deficient in a natural soil, natural selection leads to establishment of plants that store a higher concentration of that nutrient in the seed, for the benefit of the succeeding generation. This revised version was published online in July 2006 with corrections to the Cover Date.     

Water Requirements of Safflower Entries in Middle Egypt

Two promising selected land races of safflower ( Carthamns tinctorious L.) designated as line 11 and line 13, together with the local variety Giza 1 , were examined under three levels of moisture depletions, i.e. 40, 60 and 80 % ASMD at Fayoum, Middle Egypt during 1986/87 and 1987/88 seasons. In both growing seasons, the second irrigation treatment i.e. 60 % ASMD gave the highest means for growth characters as well as seed yield and most of its components. Seed oil content per cent exhibited an increased as soil moisture depletion increased with no significant difference between entries. Safflower entries showed clear differences in some yield components which compensate each other and resulted in no significant difference in seed yield per hectar.
Consumptive use of water by safflower plants increased as the available soil moisture around the root zone increased. No significant differences were found in water consumed by safflower entries used in all experiments.
In the two experimental seasons, the best water use efficiency (WUE) for seed production was obtained also from the second treatment (60 % ASMD). The line 11 gave the best WUE.     

Genetic and environmental variability in some agronomical and botanical characters of common vetch (Vicia sativa L.)

Summary Twenty-four lines of common spring vetch (Vicia sativa L.), extracted at random from a collection of about 180 lines, were tested for four years at one location. Data on vegetative, reproductive and forage quality characters were recorded and analysed for three years. Appreciable total genetic variability was found in most vegetative and reproductive characters, and only very little in forage quality characters. Compared with lotal genetic variability, large environmental variability was observed in most vegetative and forage quality traits. Reproductive characters, in general, were less influenced in this respect.Forage and seed yield were negatively correlated, which was partly due to the influence of the number of days to flower. Selection for high forage yield is expected to improve by selecting plants with little branching, high % DM and longer stems with many leaves. Selection for high seed yield (number per unit area) is expected to improve with increased number of pods per stem.There were indications that crude fibre content was a better forage quality selection index than protein content, especially if combined with percentage of leaves in total DM. Selection for improved forage quality is expected to increase lodging.Some resistance to Apion sp. and Stemphyllium seedling rot was found in the material tested.Contribution from the Volcani Center, Agricultural Research Organization, Bet Dagan, Israel, 1972 Series, No 2050-E.     

Marker‐assisted parentage analysis reveals high individual selfing rates in tetraploid red clover genotypes selected for seed yield

Seed yield is a major breeding target in tetraploid red clover. We investigated if marker‐assisted parentage analysis can identify progeny plants with two high seed‐yielding parents in tetraploid red clover and if this technique is more advantageous than traditional half‐sib selection. Parentage analysis was successfully performed on the progeny from the 10% highest seed‐yielding genotypes from a second‐cycle family selection trial: 16.0% of progeny were identified with a high seed‐yielding father. However, progeny plants with two high seed‐yielding parents did not produce more seeds than traditionally selected progeny (27.3 g vs. 30.7 g/plant, respectively). The 10% highest seed‐yielding genotypes displayed on average 2% self‐fertilization. Four genotypes were self‐fertile with individual selfing rates up to 20%. Our results discourage the use of marker‐assisted parentage analysis to improve seed yield in tetraploid red clover when the material has been preselected for seed yield. Breeders should be aware that intensive selection for seed yield in tetraploid red clover may inadvertently lead to selection for increased self‐fertility, which may increase inbreeding in the long term.     

早熟无限结荚习性大豆子粒生长特征

大豆产量潜力受到基因型和环境条件的制约。一种基因型的密度、植株分布决定其对太阳辐射、水分和养分的利用,进而高产的形成。当群体生长所需外界要素之一不能满足时,植株间形成竞争。产量的区域间及年际间差异与这种株间竞争关系密切,最终表现为单位面积内一个或多个产量构成因子的差异,如株荚数、荚粒数、或单粒重(籽粒大小)。本研究探讨籽粒大小在调节不同密度、行距条件下产量差异及年际间产量差异的作用。多点试验表明,籽粒大小在不同节位上及不同籽粒数的荚间差异不大。然而在2粒或3粒荚内,荚基部粒比中部及顶部粒小10%,而且子叶细胞体积差异不大。在改变源库、增强光照或遮阴条件下,籽粒大小发生变化。籽粒大小与子叶细胞数相关。籽粒大小是可塑的,但即使底部节位荚较顶部节位提前15~20 d鼓粒,籽粒大小在所有节位间差异不大,所以籽粒大小与子叶细胞数的关系仍值得探讨。     

Wirkung von Impfung, N-Spät-, PK-Düngung und Beregnung auf den Kornertrag und die N-Akkumulation in den Samen von mehreren Sojabohnensorten an zwei Standorten Deutschlands

Effect of inoculation, late N- and PK-manuring and irrigation on seed yield and N-accumulation in the seed of several varieties of soybean at two locations in Germany
Effect of inoculation with rhizobium, late N- and PK-fertilization and irrigation on yield and N-accumulation in seeds of four soybean cultivars was tested in a polyfactoral experiment design.
Seed yield ranged from 11.5 to 43.7 dt DM/ha and N-accumulation in seeds from 52 to 247 kg/ha. Irrigation and inoculation were the most effective production techniques. Cultivar MA96 yielded 38.0 dt DM/ha in Frankenthal on a sandy soil when plants were irrigated and inoculated. No further yield increase was obtained with additional NPK-fertilization. Cultivar KW269 resulted in a significant higher yield (43.7 dt DM/ha) when late N-fertilization was given to irrigated and inoculated plants.     

15%克.多.福悬浮种衣剂在水稻上的应用效果研究

检测了15%克.多.福悬浮种衣剂在云南不同生态气候的7个试验点的田间应用效果。结果表明： 15%克.多.福悬浮种衣剂具有防治水稻种传、土传和苗期病虫害鼠害及促进生长发育的综合功效,能显著提高水稻的出苗率、成秧率、百株鲜重、茎蘖数、叶龄、产量等生物学指标。综合分析认为该种衣剂适合在云南省推广应用,就整体而言其最佳药种比为1:40,但不同生态气候条件对种衣剂药种比的要求不尽相同。     

Vegetative propagation of autumn cauliflower

The breeding of autumn cauliflowers is difficult because the selected plants usually die in the field, or after transplanting under glass. A technique of vegetative propagation has been devised whereby selected curds are divided into portions which are then grafted on to root stocks of winter cauliflower raised in pots in the glass-house.Flowering shoots were produced four to eight weeks after grafting and up to two grams of seed was obtained from each curd portion. Seed for further breeding was obtained from 73% of the plants originally selected.     

Effect of mass selection for seed density in populations derived from Avena abyssinica x A. sativa amphidecaploids

Summary Seed of two heterogeneous amphidecaploid Avena populations (NY79143 and NY79148) were separated into three groups based on seed density using a commercial gravity table. Bulk populations were evaluated in a field trial to test the effect of selection for seed density on agronomic characteristics, while chromosome behavior was studied on similarly selected individual plants grown in a coldframe. Selection for seed density was associated with improved agronomic characteristics for individual plants grown in coldframes but the treatment effect was not significant in the field trial. Population and treatment effects were significant for chromosome number. Mean chromosome numbers were higher in NY79148 than in NY79143, and increased with selection for seed density. Populations did not differ for mean somatic instability but did show interactive population^*treatment effects. Several generations of selection for seed density is suggested.     

Responses of Soya bean Yield and Yield Component Distribution across the Main Axis under Source–Sink Manipulation

Extensive studies have been conducted regarding the source–sink alterations on soya bean [Glycine max (L.) Merr.] yield, but limited information is available for the seed yield and distribution of yield components across main nodes under whole‐plant light‐enriched conditions. A 2‐year research was conducted at the University of Massachusetts Agronomy Farm under ambient and light‐enriched conditions for two old and two new cultivars planted with a normal density. A randomized block design was used in each year. Light enrichment was initiated at the onset of flowering by installing a 90‐cm tall wire mesh fencing (mesh hole size 4–5 cm) adjacent to the centre row and sloping away at a 45° angle and was left in place for the remainder of the growing season. Five source–sink manipulations were initiated following the establishment of light enrichment. The yield sensitivity of the two old cultivars to the changes in source strength and light‐enriched conditions during reproductive period was much greater than that of the two new cultivars. The increased yield by light enrichment in various manipulations of source–sink treatments was, in part, due to increased branch contribution. Most pods were produced at the nodes in the middle sections of the plants and appeared in higher node position in new cultivars compared with the old cultivars. Seed number per pod and seed size was quite uniform across all node positions. Seed size of both the old and the new cultivars was responsive to changes in the source–sink ratio and changes in the environment during the growth of the soya bean plant. The results suggested that soya bean plants showed several mechanisms to control or realize their excess reproductive potential in a constantly changing environment.     

Yield components,harvest index and plant type in relation to yield differences in field pea genotypes

Summary The effectiveness of yield components, harvest index and morphological characteristics as selection criteria among four field pea (Pisum sativum L.) genotypes was examined. Genotypes were grown at a wide range of plant populations (9 to 400 plants m^-2) to maximise environmental diversity.Both biological and seed yields approximately doubled from 9 to 100 plants m^-2. This response flattened from 100 to 400 plants m^-2. Differences among the genotypes were found only at 225 and 400 plants m^-2. Analysis of the yield components highlighted the plasticity and large genotype by environment interactions of field peas. The numbers of pods per plant and peas per pod were maximised when each genotype was grown as spaced plants, but the low plant numbers meant seed yields per unit area were at their lowest.Genotypic differences for plant harvest index (PHI) were also only found at 225 and 400 plants m^-2. Broad sense heritability estimates indicated that direct selection for PHI was not feasible. The inference from the yield component and PHI results was that alternative selection criteria such as physiological or morphological characteristics may be necessary for improved yield potential. Classification of each genotype indicated that low seedling vigour may be a positive attribute for crop plants of semi-leafless and conventionally leafed field peas. Selection based on any single plant attribute is unlikely to lead to dramatic improvements in the yield potential of field peas. Selection should be based on plant characteristics rather than on differences in yield components.     

花生种子大小相关性状QTL定位研究进展

花生是我国重要的油料作物和经济作物,目前国内花生的产量远远不能满足消费者的所需,进一步提高花生单产是解决花生生产供不应求的重要途径。花生种子大小相关性状是花生的重要农艺性状,对提高花生单产至关重要。本文综述了植物种子大小的调控途径以及近年来花生分子标记、遗传图谱构建、种子大小相关性状QTL定位研究中取得的进展,探讨了目前花生种子大小相关性状研究中面临的挑战和机遇,对花生产量遗传改良进行了展望。