Current status of commercial Calibrachoa cultivars as assessed by morphology and other traits

To study the morphological diversity of the popular ornamental crop Calibrachoa, traded since the 1990s, floral and vegetative characters of 91 commercial cultivars were compared to those of natural species. Floral colours were classified according to the ISCC-NBS system and the CIE LAB system. The numerical data obtained by measuring 19 floral and vegetative characters was tested with principal component (PC) analysis. Floral colour classes of commercial cultivars were divided into 37 groups according the ISCC-NBS system, whereas those of natural species were divided into 9 groups. These tendencies were readily observable in the scatter diagrams of the a* vs. b* values and the C* vs. L* values. As the result of PC analysis, six PCs were obtained. For PC4, which negatively correlated with the degree of nocturnal corolla limb closure, the majority of natural species showed negative scores whereas the majority of cultivars had positive PC4 scores. In terms of PC2 (flower size), PC3 (growth form), PC5 (floral shape) and PC6 (leaf shape), natural species were dispersed in a range wider than the cultivars. These results suggest that Calibrachoa cultivars possess more highly variable floral colour than natural species, and breeding programmes to diversify the floral colour seem to have progressed rapidly. The tendency of natural species to close the corolla limb toward evening has been removed almost completely from the cultivars. The floral size, growth form, floral shape and leaf shape of the cultivars were rather uniform compared to those of natural species.     

Growth,yield and fruit quality of ‘Van’ and ‘Stark Hardy Giant’ sweet cherry cultivars as influenced by grafting on different rootstocks

The influence of Adara, CAB 6P, Gisela 5, MaxMa 14, Saint Lucie GF 64 (SL 64), Saint Lucie GF 405 (SL 405), and Tabel rootstocks onto vegetative growth, yield and fruit quality of ‘Van’ and ‘Stark Hardy Giant’ (SHG) sweet cherry cultivars was studied during 10 years after grafting. The experiment was performed in the Ebro Valley (Zaragoza, Spain), on a heavy and calcareous soil. Significant differences in some of these parameters such as vigour, yield, fruit size, soluble solids content (SSC), titratable acidity (TA), skin colour and fruit firmness were examined among rootstocks. In general, the highest vigour, annual and cumulative yield were induced by Adara rootstock, whereas Gisela 5 induced the lowest when grafted with both cultivars. The highest yield efficiency was induced by Gisela 5 due to its low trunk cross-sectional area (TCSA), together with Adara, CAB 6P and Tabel for ‘SHG’ cultivar. Regarding fruit quality, Adara, CAB 6P and MaxMa 14 showed, in general, the highest fruit weight and the more attractive skin colour for both sweet cherry cultivars. Furthermore, the high yield shown by Adara did not significantly affect its fruit size. Cherries of trees grafted on Adara also showed high firmness, which implies a better resistance to post-harvest damage. CAB 6P showed a tendency to induce higher TA. Despite the higher firmness of fruits on Gisela 5 and its tendency to induce higher SSC and ripening index, the smaller size fruits together with the less attractive skin colour resulted in a non-interesting rootstock in terms of fruit quality for our growing conditions. Interesting correlations were found among quality parameters, such as the positive correlation showed by SSC with fruit weight and TA. The work demonstrates that the scion–rootstock combination influences some important sweet cherry attributes such as vigour, yield, fruit size, acidity, skin colour and firmness.     

Molecular Characterization of Some Apple Accessions Using DNA Markers Associated with Fruit Skin and Flesh Colour

Apple (Malus domestica Borkh.) is one of the most widely grown and economically important fruit crops in the world. Skin colour is one of the most important criteria for marketing of apple fruits. Thus, improving fruit colouring is one of the main objectives of apple breeding programs. Even though environmental conditions may affect the colouring of apple, understanding the genetic basis of colouring is important to accelerate the breeding process. In recent years, molecular biology and genetic studies were conducted to explore the molecular basis of colouring in apple. Many genes responsible for the anthocyanin synthesis were identified and their associations with colouring of apple fruit flesh and/or skin were demonstrated. In addition, some DNA markers associated with fruit flesh and skin colour have been developed for screening apple cultivars and hybrids. In this study, 90 apple accessions of international, national, and local decents were selected from the genetic resources collection. Genomic DNA was isolated from leaf tissue of all acession and screened with four different DNA markers associated with fruit flesh and skin colour. Apple accessions in the collection were characterized and their genotypes and genetic potential for fruit colouration were determined by different DNA markers. Additionally, the use of these DNA markers in different apple accessions, well-characterized cultivars and uncharacterized local and national types were investigated.

     

Preliminary trials to examine the effects of ethephon as a thinner of ‘Gala’ and ‘Jonagold’ apples

Trials in southern Tasmania examined the thinning effects of ethephon on ‘Gala’ and ‘Jonagold’ apples. Untreated controls were compared with ethephon thinning sprays applied at full bloom at 50,100,200,400,800 and 1 600 mg I“1 to both cultivars. Thinning of both cultivars was related to the concentration of the spray and in most cases logistic models were fitted. Thinning effectiveness was largely reflected in increased fruit weight and size. The ‘Gala’ fruit was still not large enough for Australian markets. Ethephon at 200 mg I“1 effectively thinned ‘Jonagold’ and produced the required increases in fruit size and weight. ‘Jonagold’ was overthinned by the high concentrations of ethephon, but this was not reflected in increased fruit weight and size. Ethephon also reduced vegetative growth at the higher concentrations which was considered an advantage. More work is required to establish specific recommendations for either cultivar.     

桃品种基因型分析及其利用

根据桃性状的遗传规律及表现，对桃育种材料的花粉育性、果实形状、果肉颜色、果肉肉质和核粘、离等质量性状进行基因型分析评价，同时讨论了白花、大久保、冈山３号、丰黄和连黄等优良种质在桃育种中的利用价值。     

Development and applicability of GBS approach for genomic studies in Japanese plum (Prunus salicina Lindl.)

Genotyping by sequencing (GBS) provides a large quantity of useful data suitable for the identification of single nucleotide polymorphisms (SNPs), facilitating accurate genomic studies in plant species. In this study, GBS-based SNPs were used to characterise 11 Japanese plum cultivars and to explore their natural allelic diversity in relation to the most important phenology events (flowering date, ripening date and fruit development period) and fruit quality traits (weight, shape, skin and flesh colour, over colour, skin and flesh chlorophyll index, flesh firmness and soluble solids concentration). GBS-based SNPs were shown to be a powerful tool for genetic diversity and other genomic studies where SNP markers were related to several traits, particularly for flowering date, ripening date, fruit development period, skin chlorophyll degradation, flesh chlorophyll degradation and flesh colour. These results represent a preliminary approach using GBS as a possible breeding tool in current and new Japanese plum breeding programmes.     

Partitioning of C-photosynthates from different current shoots neighboring with fruiting spur in later-maturing Japanese pear during the period of rapid fruit growth

To elucidate the fate of photosynthates from different current shoots and their influence on fruit growth and bud differentiation in neighboring spur complex during the period of rapid fruit growth in two late-maturing Japanese pear cultivars: ‘Atago’ and ‘Shinkou’ with contrasting fruit size, ¹³C labeling of single shoot was done to investigate of C-relations in fruit branches of eight shoot-combinations. The results showed that all of the current shoots investigated (bourse shoots of nonfruiting spur, bourse shoots of fruiting spur, extension shoot, nonfruiting spur, vegetative shoot, and water sprout) could export photosynthates to the neighboring fruit and buds. Water sprouts together with vegetative shoots, bourse shoots, and extension shoots are important source for fruit growth after shoot growth termination during the period of rapid fruit growth in production of late-maturing pears. The carbon transfer rate from the neighboring to the fruit bearing spur is depent (i) on the types of shoot which acts as C source, (ii) on the position of the fruiting spur and (iii) on the source-sink distance. Furthermore, the cultivar difference in carbon partitioning from different current shoot-combinations confirmed that the movement of photosynthates into the fruit was determined by sink strength of the fruit, and ‘Atago’ exhibited a greater relative sink strength of fruit than ‘Shinkou’. In addition, vegetative shoots are very important C sources for fruit growth in ‘Atago’ and the growth pattern of bourse shoot seriously affects C allocated to fruit in ‘Shinkou’.     

Differential effect of cultivar and harvest date on nectarine colour,quality and consumer acceptance

The influence of nectarine cultivar and the harvest date on fruit colour, fruit size, fruit quality parameters, and consumer acceptance were assessed. The analyses were carried on cultivars with different fruit taste (acidity and sweetness), from 5-years-old trees at the IRTA-Experimental Station of Lleida (Spain). The six cultivars were grouped in three pairs in which each had a similar commercial harvest date. Each pair comprised by a non-acid cultivar and an acid cultivar, except the pair of ‘Big Top^®’ and ‘Mesembrine^®’, which included two non-acid cultivars. The nectarines were harvested at 8 days intervals on five harvest dates, three of which were before the commercial harvest date, one at commercial harvest and another 1 week after commercial harvest.     

Optimising quality-parameters of apple cv. ‘Pigeon’ by adjustment of nitrogen

To improve the productivity and quality of the apple cultivar ‘Pigeon’ the influence of 5 fertigation levels (14, 42, 70, 112, 224 mg N/l) and 3 widths of herbicide strip (0.2, 0.5, 1.0 m) were investigated on growth, yield and post-harvest quality/colour development of fruit. ‘Pigeon’ apples are picked when ca. 20% of the fruit skin has turned red, the fruit are then exposed to a sunning period on the orchard floor of 2–3 weeks to enhance red colour development (80% red skin); however the internal quality deteriorates during this period. Fruit drop occurs if fruit are left on the tree to develop colour. This study focused on how to reduce the length of the post-harvest sunning period to maximise both colour development and fruit quality. It was demonstrated that 14 mg N/l resulted in a low yield, small fruit, low vegetative growth, and low N content in leaf dry matter, but good fruit colour development. Excessive N fertigation (224 mg N/l) did not produce the significantly highest yield or the largest fruit, but it did enhance vegetative growth and resulted in less fruit colouration. N fertigation influenced optimal picking date; higher N fertigation delayed the time of picking, and increased the incidence of green fruit. Fruit from the high-N treatments required more days of post-harvest sunning to obtain the comparable red skin colour than fruit from the lower N-treatments. However, when all treatments were picked at ca. 20% fruit coloration it was not possible to reduce the length of post-harvest sunning period by N-supply. Most of the post-harvest colour development occurred within the first 6–9 days following harvest; colour developed on both sides but was enhanced on the shade side of the fruit. The shade side of the fruit had a greater potential for better red colour development than the blush side of the fruit.     

黄肉猕猴桃新品种‘金桃’

 ‘金桃’是从中华猕猴桃无性系中选出的新品种。果实长圆柱形, 果皮光洁无毛, 外形美观,果肉金黄色, 风味浓, 具清香, 品质佳, 丰产, 稳产, 耐贮性好, 常温下可贮藏40 d左右。     

Assessment of genetic relatedness among mango cultivars of India using RAPD markers

Summary

DNA-based RAPD (Random Amplification of Polymorphic DNA) markers have been used extensively to study genetic relationships in a number of fruit crops. A wide genetic diversity exists in the mango fruit in India. Present day commercial cultivars originated mainly from this subcontinent. In this study, 18 commercial mango cultivars, traditionally grown in western, southern, northern and eastern parts of India, were selected to assess genetic relatedness. Total genomic DNA was extracted and subjected to RAPD analysis using 30 arbitrary 10-mer primers. Of these, 27 primers amplified mango genomic DNA. None of these primers produced unique band pattern for each cultivar. RAPD data were used to calculate a squared Euclidean distance matrix, and based on this cluster analysis was done using a minimum variance algorithm. Cluster analysis clearly showed two groups—the first consisting of western, northern and eastern mango cultivars and the second group consisting of southern cultivars. From the analysis of results, it appears the majority of mango cultivars originated from a local mango genepool and were domesticated later.     

Comparison of the compatibility and metaxenia effects of several dessert apple and ornamental Malus cultivars with Cox’s orange pippin

Flowers of apple cv Cox’s Orange Pippin were hand-pollinated with diluted or undiluted pollen of six dessert and five ornamental Malus cultivars. Subsequent examinations of pollen tube growth, fruit set and seed numbers showed that all were compatible with Cox, though some differences were found. Pollen of four of the five ornamental Malus cvs, viz. Golden Hornet, Hillieri, Winter Gold and Aldenhamensis, was as compatible with Cox as that of the dessert cultivars. No metaxenia effects on size, weight, colour, russet, acidity or sugar content were seen in the pollinated Cox fruit.     

桃杂交后代主要经济性状遗传变异分析

对桃品种（系）１２个杂交组合１３６１个单系的后代主要经济性状的遗传变异情况进行了分析，包括Ｆ＿１开花期、果实成熟期、果实大小、颜色和风味、果形、果肉硬度、果肉颜色、丰产性、核粘离性、树体性状和综合品质等，为进一步合理配置亲本提供参考依据。     

矮凤梨短营养生长期突变材料‘14-1’的性状鉴定

菠萝栽培种(Ananas comosus var. comosus)的营养生长期较长,制约了其新品种选育效率。收集和筛选营养生长期较短的种质,可为短营养生长期菠萝新品种的选育创制中间材料。从境外收集了23份易成花的野生种质材料,自2008年起进行栽培、繁殖和性状鉴定。通过对营养生长期的比较和观察,从矮凤梨(A. comosus var. nanus)的体胚苗中发现了1份营养生长期显著缩短的突变材料‘14-1’,其营养生长期约6个月(原品种约12个月),1年开花2次,具有极易成花等特点。‘14-1’无性繁殖后代遗传性状稳定,可作为短营养生长期菠萝育种的亲本资源。     

苹果杂交后代经济性状的遗传变异分析

以富士、新红星等苹果品种为亲本组配11个杂交组合,获得482棵杂交单株.对杂交后代的开花株率、花量、果形、果实色泽、风味和果实综合品质等遗传变异进行了分析探讨.     

荒漠化地区南瓜品种适应性栽培性状比较

对27个不同南瓜地方品种在宁夏干旱风沙区进行适应性栽培比较试验。试验结果表明,红芳香南瓜、西小南瓜、红美丽南瓜、现代黄栗和红英南瓜果型大小适中,果皮、果肉颜色受市场欢迎,并且抗白粉病能力强,建议在宁夏中部干旱地区栽培。     

优质大果杨梅新品系乌紫杨梅的生物学特性及其RAPD鉴定

乌紫杨梅是从浙江省象山县的自然实生资源中选出的一个优质、大果、早熟杨梅新品系。乌紫杨梅果实正圆形,果面紫黑色,单果重为23.49g;总糖、可溶性固形物和花色苷含量分别为83.6mg/g、13.26%、0.50mg/g,显著高于东魁杨梅;总酸为0.92%,比东魁略低;成熟期为6月15-24日,比东魁杨梅早7～10d。RAPD分析显示,乌紫杨梅新品系母本树与乌紫杨梅嫁接后代(嫁接第1代、第2代、第3代、第4代)的相似性极高,为0.94-0.98;他们之间的遗传距离也最小。而乌紫杨梅及嫁接后代与东魁、炭梅、水梅的之间相似性较低、遗传距离也相距较远。上述结果表明乌紫杨梅是一个不同于其他杨梅品种、后代表现稳定的大果、优质杨梅新品系。     

东北寒地96份李种质资源表型性状遗传多样性分析

为了深入了解李（Prunus L.）种质资源表型性状的变异特点和多样性,按照《李种质资源描述规范和数据标准》,对黑龙江省农业科学院牡丹江分院李资源圃内保存的96份寒地李种质资源20个描述型表型性状进行观测和描述,对16个数量型表型性状进行相关性、聚类、主成分等分析。结果表明,20个描述型性状,共观测到66个变异类型,其中叶片形状、果皮颜色、果核形状等变异范围较大。Shannon-Wiener信息指数（H）和Simpson遗传多样性指数（D）变化范围分别为0.3768 ~ 1.3993和0.2188 ~ 0.7196,其中果皮颜色（H：1.2093,D：0.6814）、叶片形状（H：1.1227,D：0.5484）等性状多样性指数较高。16个数量型性状中,单果质量变异系数最大,为61.32%;果形指数变异系数最小,为8.72%。聚类分析将96份寒地李种质资源在欧式距离22处将各种质资源分为3大类群,其中第Ⅰ类可用于选育离核、抗性强的品种;第Ⅱ类可用于选育抗性强、丰产品种;第Ⅲ类可用于选育果大、可食率高、离核品种。主成分分析结果表明,前5个主成分累计贡献率达到78.191%,主要有果实纵径、果实横径、1年生枝粗等性状,主要反映了果实大小和枝条性状因子,果实性状对于东北寒地李种质资源表型性状变异的贡献率最大,一年生枝条次之。结合相关性分析结果,16个数量型性状可简化为果实纵径、果实横径、叶片宽、果核横径、果形指数、叶片长、1年生枝粗7个主要指标,提高了寒地李种质资源评价和选育鉴定工作的效率。性     

Development and evaluation of in vitro somaclonal variation in strawberry for improved horticultural traits

Strawberry cultivation is not popular in Bangladesh due to the unpredictable climatic conditions and lack of proper cultivars. Using somaclonal variation, several new promising selections were generated and evaluated for their flowering and fruiting ability, adaptability and sustainability. To induce variation, plants were regenerated using various tissue culture techniques. Our results suggested that a high concentration of BAP in culture medium successfully resulted in the induction of somaclonal variation. Among the tissue culture techniques adopted in this study, meristem culture was most effective for induction of somaclonal variation. Twenty five putative somaclones with better horticultural features were subsequently selected and field evaluated for three clonal generations. Several of the selections reverted back to their original phenotype within 2–3 vegetative propagations. Three of the stable selections were distinct from each other in terms of fruit and other horticultural characters, and have potential for commercial cultivation in Bangladesh.     

Effects of suboptimal low temperatures on plant architecture and flowering in muskmelons Cucumis melo L.

Summary

The effects of suboptimal cold temperatures were investigated in an array of vegetative, reproductive and leaf characters in 34 cultivars, both open pollinated and hybrid, of melons, Cucumis melo. The cultivars were grown in two treatments: (i) a heated greenhouse (T1) that produced temperatures similar to those used in commercial cultivation in winter; and (ii) an unheated greenhouse (T2) that produced significantly lower night-time temperatures than T1. Plants grown in T1 had significantly longer main stems and internode lengths, more nodes and more potassium in their leaves but less leaf biomass than plants grown in T2. Plants from T2 also had more green and yellow leaf colour than plants from T1. Open pollinated cultivars had significantly longer main stems, more nodes and more green and yellow leaf colour than hybrid cultivars. Significant differences were found among the cultivars in all traits.