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  • Author or Editor: Qi Sun x
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Floral scents emitted from eight cultivars of cut lily flowers (Lilium) were analyzed. Floral volatiles were collected by headspace adsorption on sorbent tubes and analyzed by gas chromatography–mass spectrometry (GC/MS) using a direct thermal desorption. Fifty volatile compounds were identified. Nine compounds were detected in all lilies, whereas 20 compounds were detected in all scented lilies. The results revealed that non-scented lilies emitted trace amounts of volatile compounds, whereas scented lilies emitted high levels of volatile compounds. Monoterpenoids and benzenoids were the dominant compound classes of volatiles emitted from scented lilies. Myrcene, (E)-β-ocimene, linalool, methyl benzoate, and ethyl benzoate were the major compounds of the aroma of scented lilies; 1,8-cineole was also a major compound in the two scented oriental × trumpet hybrid lilies. Scent emissions occurred in a circadian rhythm with higher levels of volatiles emitted during the night. Lilium ‘Siberia’ was selected as a model to investigate the source of the emissions. GC/MS analysis of four flower parts and neutral red staining revealed that tepals were the source of floral scent.

Free access

Different pollinators exhibit different adaptability to plants. Here, we compared the performance in visiting frequency and pollination efficiency among three bee pollinators (Bombus terrestris, Apis cerana, and Apis mellifera) on greenhouse-grown northern highbush ‘Bluecrop’ blueberry plants and evaluate their effects on yield and fruit quality. Our results indicated that the duration of daily flower-visiting of B. terrestris was 24 and 64 minutes longer than that of A. cerana and A. mellifera, respectively, and the visiting time of a single flower for B. terrestris was substantially shorter than the other two bee species, and pollen deposition on the stigma from single visit by B. terrestris was twice and three times that of A. cerana and A. mellifera, respectively. The yield of individual plants pollinated by B. terrestris showed an increase of 11.4% and 20.0% compared with the plants pollinated by A. cerana and A. mellifera, respectively, with the rate of Grade I fruit (>18 mm diameter) reaching 50.8%, compared with 32.9% and 22.5% for A. cerana and A. mellifera groups, respectively. Moreover, the early-to-midseason yield of plants pollinated by B. terrestris was higher, and the ripening time was 3 to 4 days earlier. An artificial pollination experiment demonstrated that seed set of high (≈300), medium (90–110), and low (20–30) pollination amounts were 43.0%, 42.5%, and 10.5%, respectively, and the corresponding mean weights of single fruits (related to the seed number inside) were 2.8, 2.7, and 1.2 g, respectively. The highly efficient pollination of B. terrestris was attributed to its behavior of buzz-pollination. Therefore, it is preferential for pollination of ‘Bluecrop’ blueberry in the greenhouse.

Open Access

Variegation in Vitis hybrids was investigated to confirm the inheritance as a single, recessive gene as previously proposed and commonly observed in breeding programs. Variegated leaves have ornamental appeal, but the phenotype is sublethal in some environments. Twenty-nine grape families were characterized for variegation including F1, S1, and S2 populations. The majority segregated 3 wild type (WT):1 variegated and were supported by chi-square tests. Four populations had segregation ratios supporting 15:1 or 1:1 models, and a unique flecking phenotype was identified in a Landot 4511 S1 population that suggested the interaction of two recessive loci. A variegated parent was selfed to produce progeny with no WT offspring and was segregated 0:1. Marker trait associations including bulk segregant analysis (BSA), genome-wide association mapping, and quantitative trait loci (QTL) mapping was used on three populations. On chromosome 14, Lvar1 was identified and mapped to 24.5 to 29.5 Mb and associated closely with rhAmpSeq marker 14_27607541. Lvar2 was associated with rhAmpSeq marker 11_18433819 on chromosome 11 at 12.2 to 18.4 Mb. The identification of two loci and the segregation data in some populations suggest that grape breeding germplasm segregates for two recessive loci. The pedigree records suggest that ‘Frontenac’ inherited one of these loci, and that Landot 4511, an ancestor of many populations tested in this experiment, may carry two loci. A total of 252 candidate genes were identified at these loci, including a key target—adenosine triphosphate (ATP)-dependent zinc metalloprotease FtsH6, involved in photosystem II and similar to the var2 mutant in Arabidopsis. This knowledge can help breeders select for ornamental grapevines or eliminate variegation from their breeding programs.

Open Access

Grape (Vitis) production and fruit quality traits such as cluster size, berry shape, and timing of fruit development are key aspects when selecting cultivars for commercial production. Molecular markers for some, but not all, of these traits have been identified using biparental or association mapping populations. Previously identified markers were tested for transferability using a small (24 individual) test panel of commercially available grape cultivars. Markers had little to no ability to differentiate grape phenotypes based on the expected characteristics, except the marker for seedlessness. Using a biparental interspecific cross, 43 quantitative trait loci (QTLs) (previously identified and new genomic regions) associated with berry shape, number, size, cluster weight, cluster length, time to flower, veraison, and full color were detected. Kompetitive allele-specific polymerase chain reaction markers designed on newly identified QTLs were tested for transferability using the same panel. Transferability was low when use types were combined, but they were varied when use types were evaluated separately. A comparison of a 4-Mb region at the end of chromosome 18 revealed structural differences among grape species and use types. Table grape cultivars had the highest similarity in structure for this region (>75%) compared with other grape species and commodity types.

Open Access