CHARACTERIZATION AND BEHAVIOUR OF PISTACHIO CULTIVARS IN CATALONIA (SPAIN)

Since 1983, seventy Pistacia vera L. cultivars have been introduced in the pistachio collection at IRTA - Mas Bové. Results of the characterization and behaviour of 53 cultivars (29 females and 24 males) from 10 countries are presented. Cultivars enclosed were observed at least during 3 flowering seasons. Tree and fruit trait records and behaviour of cultivars from this collection are completed with data from other plots.

Pistachio flowering season at Mas Bové occurs during April and it lasts on average 12 days for both sexes. Early blooming female cultivars are 'Aegina', 'Batoury', 'Mateur' and 'White Ouleimy', while 'Joley', 'Kerman' and 'Ouleimy' are late flowering. Early male bloomers are 'A', 'B' and 'Peters', and several selected clones are late bloomers.

Cultivars showed important differences in vigour. Some female cultivars are vigorous, as 'Boundouky', 'Mateur' and 'Ouleimy', and some showed lack of vigour, like 'Bronte', 'Kerman', 'Sfax' and 'White Ouleimy'. Within male cultivars, 'B', 'M-P3' and 'Peters' are vigorous, while 'Enk' and 'M-47' appear to be of reduced vigour.

Regarding juvenility of cultivars, important differences were observed. Thus, for female cultivars the juvenile stage was of 3 to 8 years, after grafting or budding in orchard, being 'Batoury', 'Kerman' and 'Sfax' early bearers and 'Bianca', 'Boundouky', 'Red Jalap', etc. late nut producers. The juvenile period of male cultivars appeared to be shorter than of females (2–6 years), being early pollen producers 'B', 'C', 'Enk', 'M-25 A' and 'M-502', and late pollen producers 'M-8', 'M-37' and 'M-47'. So far, in relation to productivity during the first years, cultivars like 'Aegina', 'Ajamy', 'Joley', 'Larnaka', 'Mateur', 'Ouleimy' and 'Sfax' appeared to be promising.

Fruit records of samples from young producing trees were taken. Some important fruit characters were assessed: weight, size, shelling percentage, dehiscence and shape. Records of weight and size showed that nuts from some cultivars as 'Ajamy', 'Kerman', 'Ouleimy' and 'White Ouleimy' were larger than other like 'Bianca', 'Boundouky' and 'Bronte'. The shelling percentage of nuts was variable, giving 'Ajamy' and 'Boundouky' high yields and 'Ashoury' and 'Red Jalap' lower yields. Shell dehiscence is very variable, showing 'Ajamy', 'Ashoury', 'Iraq' and 'Sfax' high percentages of split shells, while 'Bianca Regina', 'Bronte', 'Insolia', 'Latwardy', 'White Ouleimy' and other gave low percentages. Pistachio nut shape, measured as the relation width/length, is also variable between cultivars. 'Aegina', 'Joley', 'Larnaka' and 'Ouleimy' are cultivars with long nuts and 'Boundouky', 'Sfax' and mainly 'Kerman' have more rounded nuts.

In addition, the use of isoenzymes to characterize this dioecious species was investigated. Fifty two cultivars (36 females and 16 males) were analysed using starch gel electrophoresis for 5 enzyme systems: aconitase (ACO), esterase (EST), phosphoglucomutase (PGM), glucose-6-phosphate isomerase (GPI) and shikimate dehydrogenase (SKD). On the base of their banding patterns some cultivars could be identified.

The information gathered so far, shows female cultivars 'Aegina', 'Larnaka' and 'Mateur', and pollinators 'B', 'M-502' and 'Peters', as the most promising.