Pigments in the fruit of red-fleshed kiwifruit (Actinidia chinensis and Actinidia deliciosa)

Kiwifruit cultivars (Actinidia chinensis and A. deliciosa) generally have fruit with yellow or green flesh when ripe. A small number of genotypes also have red pigments, usually restricted to the inner pericarp but varying in intensity and in distribution within the fruit. Carotenoids, chorophylls, and anthocyanins were extracted from the fruit pericarp of such red-fleshed kiwifruit selections. Pigments were analyzed by HPLC and identified by comparison with authentic standards and by liquid chromatography-mass spectroscopy to obtain a tentative identification of the major anthocyanins in red-fleshed kiwifruit. The yellow and green colors of the outer fruit pericarp are due to different concentrations and proportions of carotenoids and chlorophylls. The red color found mainly in the inner pericarp is due to anthocyanins. In the A. chinensis genotypes tested the major anthocyanin was cyanidin 3-O-xylo(1-2)-galactoside, with smaller amounts of cyanidin 3-O-galactoside. In the A. deliciosa genotypes analyzed, cyanidin 3-O-xylo(1-2)-galactoside was not detected; instead, the major anthocyanins identified were cyanidin 3-O-galactoside and cyanidin 3-O-glucoside. However, the two species did not differ consistently in anthocyanin composition.     

Carotenoids in white- and red-fleshed loquat fruits

Fruits of 23 loquat ( Eriobotrya japonica Lindl.) cultivars, of which 11 were white-fleshed and 12 red-fleshed, were analyzed for color, carotenoid content, and vitamin A values. Color differences between two loquat groups were observed in the peel as well as in the flesh. beta-Carotene and lutein were the major carotenoids in the peel, which accounted for about 60% of the total colored carotenoids in both red- and white-fleshed cultivars. beta-Cryptoxanthin and, in some red-fleshed cultivars, beta-carotene were the most abundant carotenoids in the flesh, and in total, they accounted for over half of the colored carotenoids. Neoxanthin, violaxanthin, luteoxanthin, 9- cis-violaxanthin, phytoene, phytofluene, and zeta-carotene were also identified, while zeaxanthin, alpha-carotene, and lycopene were undetectable. Xanthophylls were highly esterified. On average, 1.3- and 10.8-fold higher levels of colored carotenoids were observed in the peel and flesh tissue of red-fleshed cultivars, respectively. The percentage of beta-carotene among colored carotenoids was higher in both the peel and the flesh of red-fleshed cultivars. Correlations between the levels of total colored carotenoids and the color indices were analyzed. The a* and the ratio of a*/ b* were positively correlated with the total content of colored carotenoids, while L*, b*, and H degrees correlated negatively. Vitamin A values, as retinol equivalents (RE), of loquat flesh were 0.49 and 8.77 microg/g DW (8.46 and 136.41 microg/100 g FW) on average for white- and red-fleshed cultivars, respectively. The RE values for the red-fleshed fruits were higher than fruits such as mango, red watermelon, papaya, and orange as reported in the literature, suggesting that loquat is an excellent source of provitamin A.     

Assessing genetic diversity of <Emphasis Type="Italic">Pyrus</Emphasis> spp. in the central Zagros mountains based on morphological characters

The morphological diversity and relationship among 138 pear genotypes, including 11 commercial cultivars and 127 wild pear accessions from central Zagros mountains located in the west of Iran, based on 64 morphological characters were studied. The higher coefficient of variation indicated that high level of variation was belonged to the petiole stipule, fruit the relative area of the skin color, fruit relative area periphery rust dents end, fruit relative blight on an area of skin, fruit curved tail, fruit dents end, fruit depth dents end, fruit relative area periphery patina tail connection characters. Pyrus communis L. and Pyrus glabra Boiss. species were the highest and the shortest tree, respectively. According to the cluster analysis, 138 genotypes were clustered into nine main groups. Principal components analysis revealed that the first three components accounted for 68.77 % of the total variation in data. Moreover, 19 factors justified 72.57 % of the total variation based on factor analysis. The research results showed that the Zagros mountains are the centers of diversity of pear. Therefore, it is necessary to use the Iranian genotypes as the genetic resources for improving the morphological characters of pear.     

Morphological characterization of snake melon (<Emphasis Type="Italic">Cucumis melo</Emphasis> var. <Emphasis Type="Italic">flexuosus</Emphasis>) populations from Palestine

Genetic diversity in 50 snake melon accessions collected from Palestine (West Bank) was assessed by examining variation in 17 phenotypic characters. These accessions belonged to four important landraces of Cucumis melo var. flexuosus: Green “Baladi” (GB), white Baladi (WB), green Sahouri (GS), and white Sahouri (WS). Principal component analysis (PCA) and a dendrogram were performed to determine relationships among populations and to obtain information on the usefulness of those characters for the definition of cultivars. PCA revealed that secondary fruit skin color, flesh color, primary fruit skin color, and secondary skin color pattern were the principal characters to discriminate melon accessions examined in the present study. According to the scatter diagram and dendrogram, landraces of C. melo var. flexuosus: GB, WB, GS, and WS formed different clusters. However, based on Euclidean genetic coefficient distances, GB and WB had the least degree of relatedness with GS and WS, indicating distantly related landraces (Baladi and Sahouri). On the other hand, the highest degree of relatedness was detected between WS on one hand, and both GS and WB on the other indicating closely related cultivars. Fruit traits variability among the different snake melon landraces was evaluated and discussed in this study. This evaluation of fruit trait variability can assist geneticists and breeders to identify populations with desirable characteristics for inclusion in cultivars breeding programs.     

The Pacific yam (<Emphasis Type="Italic">Dioscorea nummularia</Emphasis> Lam.), an under-exploited tuber crop from Melanesia

This study aims to explore the potential of Dioscorea nummularia Lam. and to gather information as a prelude to its improvement by plant breeding. After a taxonomic clarification and a review of the botanical data, its geographical areas of origin and distribution are determined. A germplasm survey conducted on nine islands of Vanuatu enabled the collection of 110 accessions corresponding to 84 cultivars. These were grouped into: (1) wild forms under domestication, (2) annual types, (3) perennial-type cultivars of D. nummularia and (4) natural interspecific hybrids with D. alata L. Within each group, remarkable morphological variation exists for stem spininess, leaf shape, emerging leaf colour, tuber shape and tuber flesh colour. Selected accessions examined for ploidy had chromosome numbers ranging from 2n = 3x = 60 to 2n = 6x = 120. Chloroplast counts conducted on stomatal guard cells confirmed the variation in ploidy levels. Eight different male cultivars were studied for pollen fertility, but <5% of the pollen grains appeared to be fertile when stained with acetocarmine. However, profuse flowering and synchrony favour pollination and result in fruit set. All accessions are resistant to anthracnose. Viruses were detected but are morphologically not discernible, with no incidence on yield. Physicochemical analyses of tubers from 16 accessions revealed that D. nummularia and interspecific hybrids have high percentages of dry matter (mean of 33.11%) and starch (82.81%). The Pacific yam could be improved through conventional hybridisation or used for interspecific crosses with related economically important species. Recommendations are made for further research.     

Wild melon diversity in India (Punjab State)

We present here the first comprehensive genetic characterization of wild melon accessions from northern India. The genetic diversity among 43 wild melon accessions collected from the six agro-ecological regions of the Punjab State of India was assessed by measuring variation at 16 Simple Sequence Repeat (SSR) loci, morphological traits of plant habit and fruit morphological traits, two yield-associated traits, root nematode resistance and biochemical composition (ascorbic acid, carotenoids, titrable acidity). Variation among accessions was observed in plant habit and fruit traits and wild melon germplasm with high acidity and elevated carotenoid content and possessing resistance to Meloidogyne incognita was identified in the collection. A high level of genetic variability in wild melon germplasm was suggested by SSR analysis. Comparative analysis using SSRs of the genetic variability between wild melons from the north and other melons from the south and east regions of India and also reference accessions of cultivated melon from Spain, Japan, Korea, Maldives, Iraq and Israel, showed regional differentiation among Indian melon accessions and that Indian germplasm was not closely related to melon accessions from other parts of the world. A highly drought tolerant accession belonging to var. agrestis Naud. was also identified.     

Genetic differentiation of watermelon landrace types in Mali revealed by microsatellite (SSR) markers

This study describes the genetic differentiation of a collection of 134 watermelon landrace accessions from Mali, representing red fleshed dessert and white fleshed seed and cooking type watermelons from five regions, plus three commercial dessert type cultivars with red flesh. The material was represented by in total 397 plants and was analysed using 24 microsatellite primer sets, which differentiated 129 alleles across all loci. Analyses of molecular variance ascribed 51 % of the variation among the landrace accessions, and 14 % of the variation could be ascribed to the regions. Partitioning the accessions into use groups (dessert, cooking, seed processing) explained 25 % of the variation. When categorising the accessions further into 10 landrace types, differentiated on the basis of use groups, local accession name, flesh colour and seed phenotype, these landrace types explained 26 % of the variation. Analysis with the software Structure revealed that the accessions with confidence could be separated into two major genetic groups, related to flesh colour (red and white) of the watermelon fruits. The same analysis further indicated that the material may be differentiated into eight genetic sub-groups. One group included again the red fleshed dessert types with local and commercial origin, while the remaining seven genetic sub-groups comprised the white fleshed landrace types used for seed processing and cooking, as well as white fleshed types of one dessert type. Some of the seed and cooking types were to a large extent different and assigned to one genetic sub-group each. A Mantel test, based on geographical and genetic distance matrices showed a positive correlation, indicating that seed exchange has not overcome local adaptation.     

Changes in seed Morphology, Dormancy and Germination from wild to Cultivated Hyacinth bean Germplasm (Lablab purpureus: Papilionoideae)

Morphological and physiological seed characteristics of the hyacinth bean (Lablab purpureus) were investigated in a set of 18 different germplasm accessions, from wild over semi-domesticated forms to landraces and current cultivars. The objective of this study was to improve the understanding of the domestication of this tropical legume crop. Wild accessions were easily distinguished by morphological characters, such as small, greyish-brown, mottled seeds. Cultivated or semi-domesticated forms showed a much wider variation in size, colour and shape. Seed mass of cultivated accessions reached up to almost 10 times that of wild accessions. Most wild accessions showed a greater spread of germination and larger proportions of hard seeds, up to about 70%, than most cultivated and so-called semi-domesticated accessions. Cluster analysis applied separately to morphological and germination data and a subsequent discriminant analysis did not help integrating the morphological variability observed. The presumed occurrence of semi-domesticated accessions within the germplasm tested as well as the crop's origin from Africa alone or both Africa and Asia are debated on the basis of seed germination and hard seed coat dormancy.     

Collection of Lupinus angustifolius L. Germplasm and Characterisation of Morphological and Molecular Diversity

Lupinus angustifolius L. is a Mediterranean species, domesticated in the 20th century, representing an important grain legume crop in Australia and other countries. This work is focused on the collection of wild germplasm and on the characterisation of morphological and molecular diversity of germplasm accessions. It reports the collection of 81 wild L. angustifolius accessions from the South and Centre of Portugal, available at the ‘Instituto Superior de Agronomia Gene Bank’, with subsequent morphological and molecular characterisation of a selection of these and other accessions. A multivariate analysis of morphological traits on 88 L. angustifolius accessions (including 59 wild Portuguese accessions, 15 cultivars and 14 breeding lines) showed a cline of variation on wild germplasm, with plants from Southern Portugal characterised by earlier flowering, higher vegetative development and larger seeds. AFLP and ISSR molecular markers grouped modern cultivars as sub-clusters within the wider diversity of wild germplasm, revealing the narrow pool of genetic diversity on which domesticated accessions are based. The importance of preserving, characterising and using wild genetic resources for L. angustifolius crop improvement is outlined by the results obtained.     

The influence of European and American wild germplasm in hop (<Emphasis Type="Italic">Humulus lupulus</Emphasis> L.) cultivars

Microsatellite variation at the nuclear and chloroplast genomes was evaluated for wild European and wild American hops, in order to assess the genetic diversity and origin of cultivated hops. Seven nuclear loci and 32 chloroplast loci were used in the analysis of 182 hop accessions including wild European (68), wild American (48), and cultivars (66). A total of 116 alleles were identified using 7 nuclear microsatellites showing different averages of polymorphism and distribution in the wild American and European accessions and cultivars. Two main groups were established as revealed by several statistical analyses; one including European wild accessions and cultivars and a second group consisting of American wild accessions. Three polymorphic chloroplast microsatellite loci were detected, six alleles were scored which defined a total of five haplotypes that were exclusive or presented different distribution between American and European wild accessions. A major influence of the wild European haplotypes was detected among hop cultivars. To the best of our knowledge, this is the first work reporting the use of chloroplast microsatellites in hops.     

Molecular and morphological data reveals new insights into genetic diversity and population structure of Chinese cherry (<Emphasis Type="Italic">Prunus pseudocerasus</Emphasis> Lindl.) landraces

Chinese cherry (Prunus pseudocerasus Lindl.) is an indigenous fruit crop with high nutritional and ornamental value. It is widely cultivated in China, and many landraces have accumulated in large distribution regions. Genetic diversity analysis of Chinese cherry landraces is useful for breeding programs, as it helps to select genetic material to be used for further crossing. In this study, 110 Chinese cherry accessions from nine populations were assessed using fifteen morphological traits and seventeen ISSR markers. High average coefficient of variation (CV?=?17.43%) was detected based on morphological analysis. For molecular characterization, the global gene diversity (h?=?0.2816) and Shannon information index (I?=?0.4253) suggested a moderate high level of genetic diversity. Model-based STRUCTURE and principal coordinate analysis revealed three and two major gene pools based on morphologic and molecular data, respectively. Distinct distribution patterns of genetic variation between samples from southwest China and north China indicated two potential original domestication locations. We inferred that botanical features such as predominantly selfing characteristics, long lifespan, and insects-pollinated trait lead to the survival of abundant genetic variation and special genetic structure. This study provided morphological and molecular evidences for understanding genetic diversity and new insights into genetic consequence of populations for Chinese cherry landraces. Important implications for breeding programs and resources conservation were also provided.     

Diversity among melon (Cucumis melo L.) landraces from the Indo-Gangetic plains of India and their genetic relationship with USA melon cultivars

We report here the first broad genetic characterization of farmer-developed landraces of melon (Cucumis melo L.) from the Indo-Gangetic plains of India, an area overlooked in previous melon genetic diversity analyses of Indian melon germplasm. Eighty-eight landraces from three melon Groups in two subspecies (C. melo subsp. agrestis Momordica Group, and C. melo subsp. melo Cantalupensis Group and Reticulatus Group) were collected from the four agro-ecological regions (six sub-regions) of two northern states of the Indo-Gangetic plains of India, Uttar Pradesh and Uttarakhand. Significant differences were found among the landraces and eight USA Reticulatus Group reference cultivars for 18 plant and fruit traits: no. of primary branches per plant, days to marketable maturity, sex expression, fruit shape, flesh colour, netting, no. of fruit per plant, fruit weight, shelf life, total soluble solids (°Bx), ascorbic acid (mg/100 g), titratable acidity (%), fruit length and diameter, seed cavity length and diameter, flesh thickness, and resistance to Cucumber mosaic virus. The three melon groups differed significantly for 10 of the plant and fruit traits. Cantalupensis Group and Reticulatus Group accessions were andromonoecious, and the Momordica Group was monoecious. Neighbour-joining (NJ) tree and factorial correspondence analysis (FCA) of simple sequence repeat loci also revealed a high level of genetic variability in this germplasm. The 96 melon genotypes clustered into five groups in the NJ tree analysis: the 16 Indian Reticulatus Group accessions and eight USA reference cultivars formed a distinct group; and the 60 Cantalupensis Group accessions clustered in four other groups with the 12 Momordica Group accessions in a distinct subgroup of one of the Cantalupensis groups. The FCA plot largely confirmed the NJ tree with three distinct groups, one for each melon group. The close affinity of the Indian and USA Reticulatus melons was not unexpected, but it is not clear whether it was inherent in the group and maintained as Reticulatus melons moved from India through Central Asia and Europe to North America, or the result of recent intercrossing of Indian landraces with the USA-derived cultivars and selection for a broad range of Reticulatus type melons.     

Increased phloridzin content associated with russeting in apple (<Emphasis Type="Italic">Malus domestica</Emphasis> (Suckow) Borkh.) fruit

Phloridzin is a phenolic compound unique to apple (Malus domestica (Suckow) Borkh.) and its wild relatives. Since its discovery, phloridzin has been researched for its nutraceutical properties, including anti-diabetic, anti-cancer, and antioxidant activities, making phloridzin a potential target for nutritional improvement in new apple cultivars. However, phloridzin accumulates at significantly lower concentrations in fruit than in vegetative tissues and seeds. In ‘Golden Delicious’ and its sports, we observed higher phloridzin content in peels of sports with a cuticle disorder termed russet. In russeted apples, the smooth, waxy fruit cuticle is partially or entirely replaced by a corky layer, induced through environmental and genetic effects. To understand the variation of phloridzin content and fruit russet in apple fruit, we surveyed 108 accessions with variation in russeting from the USDA-ARS Malus germplasm collection in Geneva, NY. Russeting in apple fruit ranged from 0 to 100%, and phloridzin content ranged from 24.3 to 825.0 μg/g in peels. Mean phloridzin content varied significantly between russeting groups; in groups with light (0–5%), medium–high (70–80%), and high (90–100%) russeting mean phloridzin content was 115.2, 591.2, and 378.8 μg/g, respectively. We observed that genetic factors and russeting are strong predictors of phloridzin content in peels, but not fruit flesh or leaves. Conversely, other peel phenolics are negatively associated with russeting. We observed variable phloridzin content related to russet incidence during fruit development in ‘Golden Delicious’ (low to medium russet) and its sports, ‘Empress Spur’ (low russet), ‘Razor’ (complete russet), and ‘Sergeant Russet’ (medium to high russet).     

Analysis of morphological,pomological and yield characteristics of some apricot germplasm in Turkey

The purpose of this study was to characterize the Irano-Caucasian apricot germplasm that was collected in Anatolia, Turkey. Fifteen (pomological, phenological, and yield) parameters were studied in this germplasm, consisting of 128 apricot cultivars and types. A wide variation was found in harvest season, fruit yield, total solids soluble (TSS), total acidity, fruit, pit, and kernel mass. Most of the cultivars and types had a relatively small fruit size; only seven had a fruit mass ≥50 g. In general, fruits had yellow skin ground color and flesh color as well as mostly sweet kernels and high TSS. While there was a high correlation between fruit, pit and kernel mass and also between TSS and total acidity, a low or no significant correlation was determined between other pomological or phenological characteristics. The Levent apricot type possessed a substantially late ripening with a total period of 190–200 days for fruit development, a characteristic that makes this apricot type highly suitable for breeding studies.     

Characterization of a landrace collection for Tomàtiga de Ramellet (Solanum lycopersicum L.) from the Balearic Islands

Tomàtiga de Ramellet (Ramellet) is a traditional long-storage tomato from the Mediterranean Islands of Mallorca, Menorca, Eivissa (Ibiza), and Formentera (Balearic Islands). To investigate the observed phenotypic and shelf life variability within local varieties, we studied 142 accessions characterized as Ramellet varieties, and 29 accessions representing other local varieties. The 171 accessions constitute a new germplasm collection at the University of Balearic Islands (UIB). The evaluation of the collection demonstrated wide variability in most agronomic, morphological and quality traits of Ramellet accessions and clearly differentiates them from other local varieties with respect to fruit shape, size, fruit composition, and fruit storage. All accessions of Ramellet evaluated have the ripening mutation alcobaça (alc), suggesting an important role for this variant in controlling shelf life. Results of evaluation also showed wide variability between the Ramellet accessions for storage time, suggesting that other traits like fruit size and composition may play a role in fruit conservation. Observed variation within the Ramellet accessions is consistent with a genetically variable population or landrace group. The establishment of this collection will help prevent genetic erosion of this local landrace group and constitute a resource for future investigation and breeding.     

Exploring an East Asian melon (<Emphasis Type="Italic">Cucumis melo</Emphasis> L.) collection for parthenocarpic ability

In melon (Cucumis melo L.), the amount of fertile pollen decreases at low temperature during winter and early spring and thereby restricts fertilization. A promising way to overcome this problem is to develop parthenocarpic cultivars. Parthenocarpic cucumber and squash, but not melon cultivars are available. In this study, we explored 172 accessions from an East Asian melon collection and identified accessions that exhibited strong parthenocarpic ability throughout the year. Crosses between parthenocarpic accessions and a non-parthenocarpic cultivar, and among parthenocarpic accessions indicated that parthenocarpy may be inherited in a recessive manner and is likely controlled by the same gene or genes in these accessions. The parthenocarpic indices, such as the size and number of parthenocarpic fruits, differed among the cultivation periods, indicating the importance of environmental factors for parthenocarpic fruit development. We conclude that it is possible to breed new cultivars with stable parthenocarpic ability throughout the year by using the identified accessions.