FIRST RESULTS OF VIGOUR AND LEAFING IN PISTACHIO PROGENIES

Little is known on pistachio (Pistacia vera L.) genetics. Most of its wide genetic variability has not been exploited to solve production drawbacks. A limited crossing programme was made in 1989/90 at IRTA- Mas Bové which produced about 2000 seedlings, derived from 31 crosses, that were planted in two nearby plots. This pistachio cultivar improvement project is providing information about the interest of some cross-combinations for two pistachio traits: vigour and leafing date.

Regarding vigour, measured as trunk diameter of the seedlings, two years after planting in randomized plots, significative differences between families were found. Results of 12 crosses (733 seedlings) showed that offspring of 'Mateur' x 'C' and 'Mateur' x 'M-502' were vigorous, while progenies derived from 'Larnaka' x 'Nazar', 'Larnaka' x 'M-502', 'Aegina' x 'Enk' and 'Larnaka' x 'M-38' were less vigorous. The cultivar 'Mateur', which is vigorous, gave usually vigorous seedlings, while 'Larnaka', which is less vigorous, produced seedlings of more reduced vigour.

In relation to the average leafing date of 15 crosses, with more than 40 seedlings each (1453 total number), significant differences between offspring were also observed. The crosses 'Sfax' x 'M-502', 'Mateur' x 'M-36' and 'Ouleimy' x 'M-502' produced late leafing seedlings, while 'Mateur' x 'M-502' and 'Mateur' x 'C' crosses gave early bud breaking families. Results of average leafing date of the progenies (1 year data) showed a significant correlation (r=0.67) with the mean date of full bloom of the parents (5 year data). Also, the results of only one year mean leafing date of parents and families gave a significant correlation (r=0.51).