E. Bellini

Qualitative evaluation of olive oils from new olive selections and effects of genotype and environment on oil quality

In the dynamically changing olive oil industry, new cultivars with greateradaptability to modern cul - tivation techniques and with high quality oils are needed. In this paper, oil quality, in terms of fatty acid compo - sition and content in phenolic compounds, was analysed for many new genotypes previously selected in a bree- ding program and cultivated in three different locations of central and southern Italy. Data on some cultivars commonly grown in each area were included for comparison. The availability of data from many genotypes cul - tivated in all three locations allowed quantitative analyses of the genetic and environmental effects on the oil qua - lity traits studied. The acidic composition varied greatly both with genotype and with environment and so did the concentration in phenols, though the effect of genotype on phenols was not significant (P=0.09). The fatty acid composition, particularly the oleic/(palmitic+linoleic) ratio, appeared predominantly under genetic control, with a broad sense heritability of 0.58 while the environmental effect explained 0.31 of the total variance. The oil con - tent in phenolic compounds, instead, had lower heritability (0.29) and was more affected by the environment, which explained 0.50 of the total variance. Few genotypes were selected as the best for each location, but none performed best in all locations. This suggests that, in olive, the highest oil quality is difficult to achieve with a sin - gle genotype in different environments, due to a strong or even predominant effect of the environment on some quality traits. More likely, combinations of genotypes and territories can produce oils with high and typical qua - lity. In this paper, we provide information on potential new genotypes with promising performances in different Italian regions. Further testing of oil quality, together with agronomic performance, is necessary prior to any release of new cultivars.

Genetic improvement of olive from clonal selection to cross-breeding programs

The origin and phylogenesis of olive (Olea europaea L.) remain unclear. The olives early domestica - tion and the use of vegetative propagation have resulted in the development of a huge number of varieties. Olive breeding has been achieved both by clonal selection and by cross-breedin g. Clonal selection has been widely adopted and has been utilized for morphological characterization and identification of germplasm, cultivars true-to-typeness and disease-free certification. The olive industry is seeking new cultivars bettersuited to modern cultivation techniques. However, cross-breeding is hindered in olive by phylogenetic, morphological, caryologic and physiological characteristics of this species. A few novel cultivars have been released in Israel and Italy in recent years. A brief summary of olive breeding programs world-wide is presented. The SeInOlTa project is eva - luating 134 genotypes pre-selected fordual-purpose use (oil and table) obtained by cross-breeding in 1971. A few papers, presented in this issue of Advances in Horticultural Science, illustrate the main results achieved by the SeInOlTa project in the period 2005-2007.

Relationship of European persimmon (Diospyros kaki Thunb.) cultivars to Asian cultivars, characterized using AFLPs

Sixty one persimmon (Diospyros kaki Thunb.) selections, including 17 Italian, 11 Spanish, 13 Japanese, six Korean, five Chinese, one Israeli, and eight of unknown origin, were evaluated for genetic differences by AFLP analysis. Relationships among cultivars were evaluated by UPGMA clustering, Neighbor Joining, and MultiDimensional Scaling. While similarities among groups were generally less than 0.60, both UPGMA and Neighbor Joining separated European and Asian cultivars. Spanish and Italian cultivars were not separated by any of the analyses, suggesting that they share a common gene pool, while Japanese, Chinese and Korean cultivars formed distinct clusters. Diversity within groups was greater than diversity between groups. Most cultivars were quite polymorphic (only 0.60–0.80 similarity between cultivars). In addition, the presence of several Japanese cultivars in the European group and a group of European cultivars nested between Chinese and Korean groups suggest that similar, but different progenitors were used in the development of the present European cultivars. ‘Kaki Tipo’ selections from different sources were clearly different by AFLP analysis, indicating that they are separate cultivars.

Identification by suppression subtractive hybridization of genes expressed in pear (Pyrus spp.) upon infestation with Cacopsylla pyri (Homoptera: Psyllidae).

The molecular interaction between pear tree (Pyrus spp.) and the phloem-feeding psylla Cacopsylla pyri (Linnaeus) was investigated through the construction and characterization of cDNA subtracted libraries. Genes expressed upon insect infestation were identified in the susceptible pear cultivar Bartlett and in the resistant selection NY10355. In both interactions, genes involved in the plant defense response were induced, confirming the observed similarity between the response to pathogens and to insects with piercing/sucking mouthparts. However, the two expression profiles were found to be different, with more genes involved in the response to biotic and abiotic stress being activated in the resistant plant than in the susceptible one. Further characterization of the identified genes could lead to the development of molecular markers associated with tolerance/resistance to pear psylla.

Anatomical differences on development of fertile and sterile pollen grains of Prunus salicina Lindl.

Anatomical changes occurring during the microsporogenic development of P. salicina Lindl. were studied in male fertile and male sterile genotypes. Male fertile pollen grains showed three well determined pore regions, without ektexine. Intine was thick and surrounded the vegetative cell. Vegetative cells enclosed the generative cells; their cytoplasm was rich in plastids, abundant RER and active mitochondria. Development of sterile pollen was different from the meiosis step. Microspores did not show germination pores and ektexine was continuous around the whole grain. Pollen grains showed an atypical shape. The tapetum persisted after the tetrad stage and showed hypertrophy and vacuole development, resulting in abnormal microspore development. Only a few pollen grains and rudiments of collapsed microspores close to the anther wall were formed at anthesis.

Pollination in Japanese plum.

Efficient pollination is fundamental for guaranteeing adequate productivity in Japanese plum. Total gametophytic self-incompatibility distinguishes all cultivars of this pomological group and makes it necessary to plant suitable pollinizers able to guarantee an adequate production of fertile pollen during anthesis. Based on studies carried out over more than a decade at the Horticulture Department, University of Florence (DOFI), observations of numerous cultivars and genotypes obtained from crosses have revealed the main characteristics required for a good pollinizer include elevated production of flowers, long anthesis period which is stable from year to year, scalar flowering, abundant pollen production, high viability and fertility of pollen grains corresponding to high germinability. It is also important that the good pollinizers show interfertility with the majority of widespread cultivars and that their flowers are very attractive to pollinating insects.