Phenotypic diversity among local Spanish and foreign peach and nectarine [Prunus persica (L.) Batsch] accessions

Phenotypic data for tree and fruit characteristics was collected over three consecutive years from a germplasm collection of 94 peach and nectarine accessions representing both traditional Spanish as well as foreign cultivars with widespread global plantings. All accessions were grown at the Experimental Station of Aula Dei located in the Ebro Valley (Northern Spain, Zaragoza) under a Mediterranean climate. Tree traits evaluated included bloom and harvest date, vigor, yield, yield efficiency and flower and leaf characteristics. Fruit traits included fresh weight, firmness, soluble solids, titratable acidity, levels of individual soluble sugars (sucrose, glucose, fructose and sorbitol), vitamin C, total phenolics, flavonoids, anthocyanins, relative antioxidant capacity and ripening index. Extensive variability was observed for most qualitative and quantitative traits with significant correlations identified between many traits. While the traditional Spanish accessions demonstrated good adaptability to the northern Spain evaluation site, opportunities for continued improvement in tree and fruit quality traits were demonstrated by an extensive phenotypic variability within the germplasm collection.     

Morphological attributes associated with early-season drought tolerance in spring durum wheat in a mediterranean environment

Impacts of drought during the reproductive development phase of wheat have been thoroughly investigated, while studies of the early-season drought effects are lacking. Field experiments were conducted to study the effect of duration of drought stress during the period from emergence to the end of tillering on the growth and performance of different wheat cultivars, and to identify traits that could be associated with the resistance to early season drought. Experiments were conducted on a Vertic Calcixerol soil in the semiarid cereal-growing region of Morocco in 1995 and 1996. Six spring durum wheat (Triticum durum Desf.) cultivars selected on the basis of variation in morphology, phenology, and zone of adaptation were subjected to four water regimes, including a well-irrigated control. The three water stress treatments were imposed by withholding water during the period from emergence to either the onset, middle, or the end of tillering. Subsequent irrigations provided adequate soil moisture for the remainder of the growing season. Results from both years were generally consistent. The differential responses of the six cultivars was mainly due to differences in numbers of kernels produced. High yields under early-season drought were attributed to high leaf area index under stress and, upon recovery, and to high tiller survival rate. The consistency observed over years in the relationships between grain yield and those traits that proved to be most associated with the resistance to early-season drought, would suggest the usefulness of these traits as selection criteria for breeding for improved drought resistance in a Mediterranean climate type of North Africa. This revised version was published online in July 2006 with corrections to the Cover Date.     

Phenotypic diversity and relationships of fruit quality traits in inter-specific almond × peach backcrosses breeding progenies

Nineteen agrochemical traits of 20 almond inter-specific backcrosses progenies were evaluated and compared for three consequence years to find out their phenotypic diversity and determine the relationships of fruit quality traits in almond × peach backcrosses breeding progenies. The variation was observed for traits of phenology parameters (blooming time, ripening time), Physical parameters (fruit weight, width, height, shape, thickness, skin pubescences, colour and flower type), chemical parameters (total sugar content, soluble solids content and acidity) and sensory parameters (attractiveness, taste, and flavor) and yield. Many fruit characteristics that are important to breeders are present in this collection. A high variability was found in the evaluated almond progenies and significant differences were found among them in all studied quality attributes. Year-by-year variations were observed for majority of traits. A significant correlation was found among the fruit height, fruit width, skin pubescences and yield. Fruit height showed a significant positive correlation with fruit weight and fruit thickness and some other traits and a negative correlation with the titratable acidity, skin pubescences and fruit flavour. A high negative correlation was found between the fruit weight and titratable acidity (?0.8). Low coefficients were got between the flower colour and skin pubescences. In addition, principal component analysis it possible to established similar groups of genotypes depending on their quality characteristics and to study relationships among pomological traits in almond progenies evaluated.     

Multivariate analysis of vineyard peach [Prunus persica (L.) Batsch.] germplasm collection

Thirty vineyard peach [Prunus persica (L.) Batsch.] genotypes were studied to determine the overall degree of polymorphism and to detect similarities among genotypes. The variation was observed for traits related to phenology, morphology, yield and fruit quality. Many fruit characteristics that are important to breeders are present in this collection. The majority of important correlations were determined between the characteristics representing fruit size (fruit width, fruit height, fruit weight and stone weight) and between those ones representing fruit quality (fruit attractiveness, taste, flavour and soluble solids content). Cluster and principal component analysis showed a considerable phenotypical diversity in the vineyard peach germplasm. Clustering of genotypes was in accordance with its purpose (fresh consumption or rootstocks production). Parameters with high discriminating values were those related to fruit size and fruit quality.     

番茄遗传资源的聚类分析研究

通过测定番茄品质特性的遗传多样性和分子标记的多态性,对番茄品种资源进行了聚类分析。结果表明,品质特性聚类分析和分子标记聚类分析最后都形成了四大类群,而且都把果实硬度大、软化速度慢、果型长圆、含水量低、可溶性固形物含量高的加工番茄聚合在了一起,说明一些分子标记可能和控制番茄加工品质特性的基因有比较紧密的连锁关系。分子标记更能灵敏地区分不同品种间的遗传差异。不同类群间品质性状的差异明显大于群内不同品种间的差异,说明聚类分析是鉴别品种资源遗传差异程度、筛选核心资源的有效手段。     

Heat stress affects vegetative and reproductive performance and trait correlations in tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>)

High ambient temperature has adverse effects on plant vegetative and reproductive development and reduces crop yield. To better understand the importance of male and female fertility for tomato fruit set ability under high temperature conditions and to test whether heat tolerance levels among and between reproductive and vegetative traits of genotypes correlate with each other, 13 tomato cultivars were subjected to long-term moderate heat (LTMH) or short-term heat shock (STHS), depending on the trait that was evaluated. LTMH caused significant decrease in performance of nearly all reproductive traits, i.e. pollen viability, pollen number, female fertility, seeded-fruit set and flower number per inflorescence, but not in inflorescence number. Considerable variation was found among cultivars, both under control and LTMH conditions. The cultivars Nagcarlang, Saladette and Malintka 101 produced a higher percentage of viable pollen under LTMH. For fruit set under LTMH condition, only cultivars that had been previously reported as being heat-tolerant produced fruits with seeds. STHS negatively affected vegetative traits concerning seedling survival and membrane stability. Correlation analysis revealed relationships between various traits within the control and heat treatments, but not between the two. Under heat stress fruit set was positively correlated with pollen viability, as well as with flower number per inflorescence. However, no significant correlations were found between vegetative and reproductive traits. Our data highlight the prominent role of pollen viability for tomato fertility under LTMH growth conditions. The observed variation in thermotolerance among different cultivars offers the possibility to decipher underlying physiological and genetic mechanisms.     

Agronomical and quality traits of runner bean germplasm and implications for breeding

White runner bean landraces are greatly appreciated in the North highlands of Spain due to their excellent culinary seed quality. Runner bean cultivars are grown like pole beans. Diversity within a runner bean collection of 31 accessions from the Iberian Peninsula (Spain and Portugal) was examined using morphological, agronomical and seed quality traits. Landraces showed significant differences for most of the agronomical and seed quality traits studied except for seeds per pod, water absorption, seed coat tenderness and floury texture. Runner bean landraces showed sufficient variability to select inbred lines for future breeding. Genotype × environment interaction was significant for days to first flowering, days to first dry pod, seeds per pod and seed length. The majority of physical and nutritional seed quality traits studied which are important to determine the commercial value of a variety were not subject to environmental influences. Different selection pressures affecting to the runner bean genetic material could have occurred in several regions of the Iberian Peninsula. Extra-large and high yielding runner bean germplasm was identified and represents a valuable source of genetic diversity that has potential for development of improved cultivars to be chosen for commercialisation. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于穿刺测试和TPA法的板栗果实质地分析

为比较不同板栗品种之间果实质地差异,采用质构仪穿刺测试和质地多面分析（TPA）法测定了16个品种板栗果实的质地特性。结果表明：板栗果实表型和质地性状变异丰富,穿刺果面硬度、果肉平均硬度、TPA硬度间呈极显著正相关,且均与果面韧性、果面脆性和紧实度呈极显著正相关（P<0.01）;单果质量和果实横径与果实硬度呈显著负相关（P<0.05）。主成分分析将17个指标（果实表型和质构仪参数指标）组合形成果实硬度、咀嚼特性、果实大小和黏附性因子4个主成分,其累计方差贡献率为89.298%。聚类分析可将这些板栗品种根据质地和表型参数分为7类,不同类别之间差异较大,表明这些特征参数可作为板栗种质资源的评价指标,为板栗鲜食品质鉴定、加工利用和品种选优提供科学依据。     

Inheritance of fruit yield in two watermelon populations in North Carolina

Elite cultivars of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) are high in fruit quality but may not be the highest yielders. The objective of this study was to estimate the heritability of, and genotypic and phenotypic correlations among, yield traits in two watermelon populations developed from crosses between obsolete cultivars with high yield and elite modern cultivars. Field trials were conducted at two locations in North Carolina (Clinton and Kinston). The data were analyzed by regressing S_0:1 progeny data on S₀ parent data to estimate narrow-sense heritability. Narrow-sense heritability estimates were low for all traits measured [total fruit weight (0.04–0.12), marketable fruit weight (0.06–0.15), total fruit number (0.04–0.16), fruit size (0.18–0.19), and percent culls (0.02–0.09) in North Carolina Watermelon 1 (NCWP1) and North Carolina Watermelon 2 (NCWP2) populations, respectively]. Estimates of broad-sense heritability were higher than estimates of narrow-sense heritability. Total fruit weight and marketable fruit weight were highly correlated (r _g = 0.97–1.00). Marketable fruit weight and fruit size used as single selection criteria in NCWP1 and total fruit number in NCWP2, were predicted to give the best correlated response for total fruit weight. Narrow-sense heritability was low for fruit yield; therefore, watermelon breeders should select based on replicated progeny rows in multiple environments to maximize gain.     

Relationship of parental genetic distance with agronomic performance,specific combining ability,and predicted breeding values of raspberry families

Previous findings in some crops suggest that parental distance is correlated with heterosis and agronomic performance. However, this pattern is not always evident in the progeny. The present study aimed to assess the relationship of parental distance with the agronomic performance of raspberry families and three estimators based on non-environmental effects: specific combining ability, general combining ability, and best linear unbiased prediction. A total of 35 genotypes, including eight open-pollinated raspberry cultivars and their 28 F₁ hybrids, were scored for vegetative and fruit traits. The relationship between estimators and parental distance ranged from 0.02 to 0.66. The estimators based on purely additive effects were superior to the per se performance of raspberry crosses. Additionally, it was observed that the specific combining ability—as an estimator associated with the parental genetic relatedness—performed poorly, and low correlation coefficients were observed for most of the traits. It was found that the degree of association for the estimators increased when narrow-sense heritability was high. It is concluded that the estimators based on only additive effects show a better association with parental relatedness, and therefore parental distance was an effective parameter in identifying crosses with high yield and large fruit size.     

设施大棚铺设银色反光膜栽培杨梅试验研究

在设施大棚杨梅园铺设银色反光膜,试验研究大棚铺设反光膜对‘临海早大梅’物候期、果实品质及效益的影响。以大树移植3年的11年生‘临海早大梅’为试材,2013年1月11日对其进行大棚覆盖,并于2月13日大棚内铺设银色反光膜,以不盖为对照,观察记载棚内外温湿度、杨梅物候期的变化,测定果实单果质量、可溶性固形物含量和每公顷产量。大棚杨梅园铺设反光膜可显著增加棚内的温度和相对湿度,使杨梅的物候期显著提早,开花期提早16天,果实成熟期提早21天,果实单果质量增加10%,可溶性固形物含量增加2.1个百分点,每公顷产量提高45.6%,净增产值1265610元。‘临海早大梅’设施大棚铺设反光膜栽培,可以显著提早成熟期,显著提高单果质量和可溶性固形物含量。     

The effect of delaying harvest date on fruit quality and storage of late highbush blueberry cultivars (Vaccinium corymbosum L.)

The effect of delaying harvest on fruit quality and storage life was measured for the late-season highbush blueberry cultivars ‘Aurora’, ‘Elliott’ and ‘Liberty’. In all three cultivars as fruit ripened, there was a steady decline in TA while SS remained stable, indicating that the fruit were becoming sweeter. This was supported by taste panel perceptions of greater sweetness associated with later harvested fruit. There was also a significant overall reduction in fruit firmness and storage life as the percentage of blue fruit at harvest increased; however, a significant interaction for storage life between crop ripeness and cultivar was observed, indicating that the fruit of some cultivars were less influenced by overall crop ripeness than others. The storage life of ‘Elliott’ was significantly affected negatively by crop ripeness, while ‘Aurora’ and ‘Liberty’ were not. ‘Liberty’ produced the highest percentage of sound fruit of the three cultivars and its fruit stored the longest, suggesting that ‘Liberty’ and ‘Aurora’ fruit can be left longer on the bush before harvesting than ‘Elliott’ without significantly damaging storage life. This would allow ‘Aurora’ to develop a sweeter flavor before shipping. The physicochemical and sensory evaluations were highly correlated, suggesting that TA, SS and firmness can be used as predictors of consumer preferences.     

番茄品质性状的遗传多样性研究

以美国和欧洲种植的11份番茄地方品种、国内部分地区1950—1980年种植过的21份常规品种和12份自育自交系为材料,对它们的主要物理特性和化学特性进行了研究。结果表明,11个被测性状在基因型间都有极显著的差异,但多数性状的广义遗传力较低。和欧美品种相比,国内品种的果型偏大、果肉偏软、果酱含量和可溶物含量偏少、番茄红素偏低。对品质特性的遗传多样性和品质改良的潜力进行了讨论。     

Impact of harvesting time and fruit firmness on the tolerance to fungal storage diseases in an apple germplasm collection

Blue mold and bitter rot, caused by Penicillium expansum and Colletotrichum gloeosporioides, respectively, are two of the most devastating diseases during and after storage of apple. The present project was conducted to evaluate the level of tolerance to these diseases in apple germplasm, and investigate possible associations with other fruit characteristics such as harvest date, firmness at harvest, softening (loss of firmness during storage) and sun-exposure. Apples were harvested at a maturation stage suitable for storage, inoculated with spore suspensions of P. expansum (127 cultivars) or C. gloeosporioides (70 cultivars), and stored for 6 or 12 weeks for early- and late-maturing cultivars, respectively. Fruit firmness was measured after harvest and after storage, and the difference was used as a measure of fruit softening. Average lesion diameter varied significantly among both early- and late-maturing cultivars. The amount of damage caused by the two diseases was significantly correlated across cultivars. Regression analyses indicated that lesion diameter was positively affected by fruit softening and negatively affected by harvest date and firmness at harvest. Impact of the independent variables was quantified with partial least squares discriminant analysis; approximately 40% of the genetic variation could be explained by these variables with harvest date being the most important. The effect of sun-exposure was analyzed on six bi-colored cultivars but the results were not conclusive. Cultivars that showed relatively small symptoms in spite of being early-maturing and/or only medium firm, may have other traits that are beneficial for storage and could therefore be especially useful in breeding programs.     

Genetic diversity and association mapping of forage quality in diverse bermudagrass accessions

Bermudagrass is a warm season grass widely cultivated for turf and fodder. Nonetheless, the grass has poor forage quality because animals that consume it fail to assimilate its organic matter efficiently. Thus, identification of the marker-trait association between simple sequence repeat (SSR) markers and forage-quality-related traits in diverse bermudagrass accessions would enable efficient selection of high forage quality bermudagrass cultivars. Association mapping of 8 forage-related-quality traits with 1474 markers was conducted in 60 diverse bermudagrass accessions from five geographical regions in China. Significant variations in eight phenotypic and physiological traits were observed among the 60 accessions. A total of 1474 alleles were amplified by 104 SSR primers. The average gene diversity and polymorphic information content for the study sample were 0.2097 and 0.1748 respectively. The clustering analysis suggested that geographic origin influenced genetic distances between accessions. A total of 76 markers significantly associated with traits at P < 0.01; 73 with a single trait and 3 with two traits each. Nevertheless, only 41 significant marker-trait associations (MTAs) were observed after Bonferroni test was separately conducted for each trait. Forty-one microsatellites had significant associations with 8 forage-quality-related traits. These markers provide a feasible means of genetically improving forage quality in bermudagrass after further authentication.     

Phenotypic diversity in cold-tolerant peanut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis> L.) germplasm

Tolerance to low temperature is an important prerequisite for optimal performance of peanut (Arachis hypogaea L.) in a number of temperate peanut-growing environments. One hundred fifty-eight peanut accessions belonging to five botanical types, known to be tolerant to low temperature (12°C) at germination, were evaluated for phenotypic diversity for 15 morphological traits in the 2001 rainy season and for 15 agronomic and two seed quality traits in the 2001 rainy and 2001/2002 post-rainy seasons. Analysis of data, using the residual maximum-likelihood approach indicated that variance components due to genotypes were significant for all traits in the rainy and for all but two traits in the post-rainy season. Clustering based on scores of nine principle components delineated four clusters. The cold-tolerant genotypes and the standard control cultivars in the four clusters differed in mean, variance, and range both during rainy and post-rainy seasons for a range of agronomic traits, indicating the diversity among the clusters. The cold-tolerant accessions were superior to control cultivars for several agronomic traits compared with their respective controls in both the rainy and post-rainy seasons, so their use in breeding should result in genetically diverse cold-tolerant high-yielding peanut cultivars.     

Analysis of tofu‐related traits by a bench‐scale tofu production method and their relationship with agronomic traits in European soybean

European tofu manufacturers are becoming more and more interested in locally grown soybeans. A prerequisite for the development of European tofu cultivars is to improve our understanding of how the environment and genetics affect soymilk and tofu quality, as well as how quality and agronomic traits are correlated. This study was based on 215 recombinant inbred lines derived from two populations and grown at three locations that were evaluated for tofu traits in a bench‐scale tofu laboratory. The heritabilities of most of the evaluated tofu traits were moderately high with h² > 0.6. We observed significant genotypic variance components, but an even stronger contribution of the location. The network analysis of the evaluated traits was population‐dependent; however, the tofu traits were not associated with any of the agronomic traits. Collectively, our results indicate the potential to improve tofu‐related traits in European soybean. The bench‐scale tofu production method provides a valuable tool to test soybean lines in breeding programmes; however, the method needs to be further improved and automated to minimize errors due to the laboratory staff.     

云南永德‘桂味’与区试品种荔枝果实品质表现

了解永德县荔枝主栽品种‘桂味’与区试品种果实品质表现，为‘桂味’品质提升和品种改良提供建议。采集30个果园的‘桂味’和7个区试品种荔枝果实，测定分析果实品质，并结合品质加权分、经济效益指数对测试品种进行评分排序。调查花期授粉源和气温以分析‘桂味’焦核率低的原因。结果表明，永德县‘桂味’荔枝平均单果重、可溶性固形物含量和可食率分别为22.53 g、19.27%和76.61%，单果重和可溶性固形物含量优于广东大部分产区；焦核率仅为44.00%，低于广东大部分产区。经济效益指数评价结果显示，7个优新品种荔枝均优于‘桂味’，依据区试品种荔枝果实品质表现，除‘岭丰糯’外其他品种初步判定引种成功‘。桂味’与大核品种‘怀枝’等混种且花期相遇，推测花粉源和授粉期间长时间低温可能是当地‘桂味’大核化的原因之一，提高‘桂味’焦核率是提质增效的技术关键‘。无核荔’‘、贵妃红’‘、冰荔’‘、仙进奉’引种区试表现较为优异，适合作为永德县荔枝的改良品种。     

Towards sweet cherry (<Emphasis Type="Italic">Prunus avium</Emphasis> L.) breeding: phenotyping evaluation of newly developed hybrids

An increasing demand for cherry production (Prunus avium L.) in Greece led to the development of new high quality sweet cherry cultivars. Self-incompatibility in cherry is one of the most challenging issues for the species’ cultivation and top breeding priority. Τhe present study focuses on the development of new hybrids with improved traits such as productivity, fruit size, organoleptic characteristics and self-compatibility. For this purpose, thirty different cultivars were crossed and produced hybrids that were evaluated according to 34 morpho-physiological characteristics. The results were analyzed using the XLSTAT (version 2014.1) software and a dendrogram was constructed using the agglomerative hierarchical clustering method. Optimal hybrid clustering was achieved when characteristics of great economic importance such as fruit shape and size, growth habit and days to blooming were included in the analysis. Based on the results, new sweet cherry hybrids with the special character of self-compatibility were developed. Our findings provide crucial new information for sweet cherry future breeding programs and cultivation.