No abstract

Accurate and rapid cultivar identification is important for breeders'‐rights protection, especially for vegetatively propagated plants. The objective of this study was to test the feasibility of developing cultivar‐specific RAPD markers in commercial strawberries (Fragaria ananassa Dutch). Efforts were focused on distinguishing between two newly developed Volcani cultivars, ‘Ofra’ and ‘Dorit’, and six other cultivars, ‘Douglas’, ‘Chandler’, ‘Oso Grande’, ‘Dover’, ‘Nurit’ and ‘Parker’. Reproducible RAPD fingerprints were generated, each containing at least one polymorphic DNA product. A combination of 10 polymorphic DNA products exhibited cultivar‐specific patterns enabling the distinction between closely related varieties, such as ‘Ofra’ (which is the progeny of ‘Dorit’ and ‘Parker’) and ‘Dorit’ (which is the progeny of ‘Nurit’ and ‘Dover’). This study shows that RAPD markers can help in the protection of breeders’ rights to strawberry cultivars.

Randomly amplified polymorphic DNA (RAPD) markers were applied in purity control of hybrid seed production of tomato [Lycopersicon esculentum Mill.). DNA from three commercial F,-hybrid cultivars and their parental lines was subjected to RAPD screening with 50 primers. Two of four primers which detected polymorphism between the parents tested, generated paternal-specific RAPDs, enabling a clear distinction to be made between hybrids and their maternal parents. In addition, combination of the polymorphic DNA products generated by these primers exhibited hybrid-specific patterns, enabling each cultivar to be identified. This result indicates the practical usefulness of RAPD markers in hybrid-tomato-seed purity-control tests and cultivar identification.The approach is advantageous in its rapidity and simplicity, particularly as an alternative for those cultivars for which lengthy and costly phenotypic tests are currently used.

BACKGROUND: In bunch cherry tomatoes (BCTs) abscission of the fruit from the bunch, rather than deterioration of fruit determines the life-span of the produce. Two abscission sites have been characterised: the joint (AJ) in the middle of the pedicel, and at the receptacle (AR) at the fruit-pedicel interphase. The type of abscission is sensitive to growth conditions; joint abscission is typical of winter harvests whereas receptacle abscission is dominant in summer harvests. The aim of the present study was to determine the effect of relative humidity (RH) in terms of water vapour pressure deficit (WVPD) during storage and shelf life on the course and site of abscission of BCTs.