Yilin Jia

When used to pollinate flowers of diploid Actinidia chinensis ‘Hort16A’, pollen from tetraploid A. chinensis or hexaploid A. deliciosa males produced fruit with higher fresh weight than did pollen from a diploid A. chinensis male. The dry matter content of the fruit was also increased once differences in the dry matter content of the seed were taken into account. These increases occurred despite slightly delayed harvest maturity and fewer well‐formed seed in fruit following pollination by the higher ploidy males. Variation in seed development following different pollen treatments could be explained largely by the genomic ratios expected in the endosperm, and the tendency of ‘Hort16A’ to produce a proportion of 2 n gametes. The results suggest that, in contrast to many other diploid A. chinensis genotypes, pollination of ‘Hort16A’ by males of higher ploidy may be beneficial in terms of fresh fruit weight.

Fruit of colchicine-induced tetraploids of Actinidia chinensis were 50% to 60% larger than those of their diploid progenitors. In addition to fruit size, fruit quality is a key issue in any commercialization of these autotetraploids. We have made the first detailed study of the effects of chromosome doubling on fruit quality parameters other than size: these attributes include flesh firmness, color, soluble solid content (SSC), dry matter content (DM), vitamin C content, fruit skin thickness, and red pigmentation distribution in red-fleshed kiwifruit. Four selections from colchicine-induced tetraploids from the yellow-fleshed kiwifruit cultivar Hort16A were trialed for the stability of their fruit quality. Analysis of fruit at harvest over 3 years showed that fruit of the induced autotetraploids were significantly softer (lower flesh firmness), had lower DM, and had a less intense golden flesh color than fruit of their diploid progenitor. During development, SSC of fruit of the autotetraploid plants started to increase earlier than in the diploid ‘Hort16A’. This has been confirmed by replicated trials. No difference was found in vitamin C content between fruit of autotetraploids and diploids. Autotetraploids had significantly thicker skins than diploid ‘Hort16A’. Induced autotetraploids from three female genotypes of red-fleshed A. chinensis showed similar trends to autotetraploids of ‘Hort16A’ in fruit flesh firmness and outer pericarp flesh color, DM, SSC, and vitamin C. All the traits analyzed indicated that fruit of the autotetraploid plants matured earlier than those of their diploid progenitors. Furthermore, red pigmentation, one of the most important traits for red-fleshed kiwifruit breeding, showed a reduction in both intensity and distribution in the autotetraploids compared with their diploid progenitors. There was considerable variation among fruit of autotetraploid plants regenerated from each diploid progenitor. Therefore, selection among the regenerants may be required to achieve the best outcome after ploidy manipulation in kiwifruit breeding.

Spirotetramat (Movento®) is a phloem‐ and xylem‐mobile insecticide developed and registered for use pre‐flowering to control armoured scale insects on kiwifruit vines in New Zealand. In a field study in 2010–11, the effectiveness of a postharvest application was investigated. A single spray of spirotetramat plus adjuvant(s) reduced the percentage of scale‐infested fruit from 49% on control vines to less than 7.5% on spirotetramat‐sprayed vines 12 months later. No residues were detected in the fruit. Applying spirotetramat with a penetrating adjuvant (Engulf®) provided the best result, with only 1.5% of the fruit infested. Despite the high pest pressure, counts of scale insect crawlers on sticky bands remained very low for 18 months after treatment. Uptake of spirotetramat into the mature kiwifruit leaves occurred in less than 24 h and was not affected by leaf age. Translocation out of the leaf was slow and decreased with leaf age, indicating that a postharvest spray should not be applied to canopies exhibiting advanced senescence. These results show that a single postharvest application of spirotetramat plus adjuvant(s) can provide excellent season‐long control of armoured scale insects on kiwifruit while minimizing the risk to crop pollinators and the potential for residues in fruit.

BACKGROUND: This paper presents a case study with wine where two statistical methods for the analysis of rating‐based conjoint analysis data were applied. Traditionally, ordinary least squares (OLS) regression is used to estimate the relative importance of the experimental factors and the part‐worth utilities of factor levels. Partial least squares (PLS) regression, which is a popular tool in sensory and consumer science, can also be used for the analysis of interval‐level conjoint data.RESULTS: Using conjoint analysis, purchase intentions for Californian red and white wine were obtained from a convenience sample of young US adults (n ≈ 250). OLS and PLS regression uncovered the same systematic patterns in the data: negative utility associated with more expensive wine, and positive utility associated with famous wine regions. While OLS regression provided more accessible top‐line results, an advantage of PLS regression was the graphical format of results. This provided easy insight to individual differences in the importance attached to the factors driving purchase intention.CONCLUSION: OLS and PLS regression can complement each other in the analysis of interval‐level conjoint data. Dual analysis can help to ensure that the right insights are drawn from the study and communicated to internal/external clients. It may also facilitate communication within project teams. © 2013 Society of Chemical Industry

Anthocyanins have diverse roles in plant reproduction and in response to both abiotic and biotic stress. By over‐expressing the apple MYB transcription factor, MYB10, we have generated apple trees, Malus × domestica Borkh. (Rosaceae), with highly pigmented red foliage due to the presence of high concentrations of cyanidin‐based anthocyanins. In this study, we investigated the impact of the high anthocyanic apple leaves on the behaviour, feeding, and life cycle parameters of the light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), a widespread herbivorous pest of apples. Behaviour of 1‐ to 3‐day‐old larvae towards red anthocyanin‐rich and green apple leaves was studied in choice and no‐choice trials, and survival, growth, and development of larvae feeding on red and green apple leaves from the neonate to pupation were compared. First‐instar E. postvittana showed a statistically significant preference for green over red leaves from three transgenic red apple lines and a preference for the less red old leaves over the bright red new leaves. This was significantly different from their behaviour towards wild type green leaves, where new leaves were selected over old. In complete darkness, first‐instar E. postvittana showed no significant preference for the green leaves, indicating that visual cues were important. Although larval survival was not greatly affected by feeding on the red foliage, larval growth and development were significantly affected by feeding on leaves from some of the transgenic red apple lines. Liquid chromatography‐mass spectrometry analysis of leaf phenolics showed that both anthocyanins and quercetin glycosides were significantly raised in the red transgenic lines compared with wild types.

Flyspeck caused by Schizothyrium pomi (anamorph Zygophiala jamaciensis) is a serious cosmetic skin disorder of Actinidia arguta kiwifruit in New Zealand In a study of the disease in 200910 the bark of all 1yearold canes was carrying large numbers of characteristic dark fruiting bodies (thyriothecia) (flyspecks) Germinating spores and hyphae of S pomi were first observed on current seasons canes in December 2009 Flyspecks were first found on fruit in midJanuary 2010 and their incidence and severity increased until harvest in February 2010 Sprays of trifloxystrobin or carbendazim applied preblossom and during flowering reduced the incidence of fruit with flyspeck at harvest by an average of 70 compared with the untreated control A single application at either of those times was similarly effective with one exception; trifloxystrobin applied as a preblossom spray failed to control flyspeck Carbendazim residues (002 mg/kg) were recorded in the fruit at harvest following an application during flowering

Various combinations of heat time and relative humidity (RH) were tested for their ability to kill Pseudomonas syringae pv actinidiae (Psa) the cause of kiwifruit canker on freshly harvested anthers artificially contaminated with this bacterium Pollen viability and Psa survival were tested after treatment Although short durations at high temperatures and high RH did kill Psa these treatments were also lethal to pollen When RH was reduced the time before pollen viability was lost increased but Psa survival was also enhanced The most promising treatment was 35C at a RH of 50 or less at which pollen viability was not affected even after 20 h but Psa did not survive when applied at 106 cfu/ml Modelling suggests that extending the time of treatment would kill higher concentrations of Psa The mechanism for Psa death at 35C is probably by a combination of heat and desiccation