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With 2 tables Abstract The breeding of new late-flowering almond cultivars is a long process, due mainly to the long juvenile phase of the seedlings. Early selection methods would improve the efficiency of breeding programmes. In this work, we investigated the use of seed germination time to select for late-flowering almonds in 136 seedlings representing six progeny from controlled pollinations performed in 2002. Germination time for seeds with mesocarp and endocarp removed was recorded during stratification, and time of leaf budbreak and flowering were recorded in the fourth and fifth leaf. Within the six progeny evaluated over 2 years, correlations between seed germination and leaf budbreak of the seedlings ranged from 0.02 to 0.43, and for the pooled data averaged 0.48. Correlations between seed germination and seedling flowering time ranged from 0.06 to 0.55, and for the pooled data were 0.50. These results indicate a relationship between times of germination of the seeds and flowering of the resulting seedlings, but the low correlations indicate that the usefulness of selection based in seed germination time will be limited.

With 2 tables Abstract The breeding of new late-flowering almond cultivars is a long process, due mainly to the long juvenile phase of the seedlings. Early selection methods would improve the efficiency of breeding programmes. In this work, we investigated the use of seed germination time to select for late-flowering almonds in 136 seedlings representing six progeny from controlled pollinations performed in 2002. Germination time for seeds with mesocarp and endocarp removed was recorded during stratification, and time of leaf budbreak and flowering were recorded in the fourth and fifth leaf. Within the six progeny evaluated over 2 years, correlations between seed germination and leaf budbreak of the seedlings ranged from 0.02 to 0.43, and for the pooled data averaged 0.48. Correlations between seed germination and seedling flowering time ranged from 0.06 to 0.55, and for the pooled data were 0.50. These results indicate a relationship between times of germination of the seeds and flowering of the resulting seedlings, but the low correlations indicate that the usefulness of selection based in seed germination time will be limited.

9 pages, 3 tables.-- Available online 17 Nov. 2004., Breaking seed dormancy is necessary for the completion of germination. Maternal tissues (integument and endocarp) appear to control seed germination, although the effect of the pollinizer has also been described. In this work, the influence of the pollinizer flowering time was studied on the stratification requirements of almond seed germination. Stratification requirements were determined in seeds (with and without endocarp) from crosses between a female progenitor and pollinizers of different flowering dates. The results showed an influence of the pollinizer in the stratification requirements of seeds with endocarp. However, no correlations were found between pollinizer flowering date and stratification requirements, which seem to be determined mainly by the female progenitor. In the case of seed stratification without endocarp, the results did not show any influence of pollinizer on stratification requirements. The observed variability within females (within or between crosses) could be due to differences in the shell characteristics, the different accumulation of inhibitors in the integument, or the genetic nature of the embryos., The work has been financed by the project AGL2001-1054-C03-01 entitled ‘‘Mejora Genética del Almendro’’ from the Spanish Ministry of Science and Technology. The authors also acknowledge the support of the Spanish Ministry of Science and Technology for the contract of Dr. P. Martínez-Gómez.

6 pages, 2 figures, 3 tables.-- Published Online: 28 Jun. 2008., Obtaining new, late-flowering almonds by crossing is a very long process, mainly due to the long juvenile period of the seedlings obtained. It would be very useful to have an early selection method to identify the late-flowering genotypes, which would increase the efficiency of the breeding programmes. In this work, a study was made of the possibility of using the chilling requirements of seeds for germination and the leafing time of seedlings as criteria for early selection of flowering time, in 502 seedlings belonging to 13 families, over a four-year period. Crossings were carried out in 1997. Seeds were stratified at 7°C. and the number of weeks necessary for germination was determined. Seedlings were planted in 1998. Between 1999 and 2002 the leafing time was recorded, and in 2001 and 2002 the time of flowering was also recorded. The results showed that, although some correlation was observed between the germination or leafing time and the flowering time, these correlations were not strong enough to be used as efficient criteria for early selection of late-flowering seedlings within each family. for which variability was limited. To obtain late-flowering cultivars. the best method is to cross progenitors which flower as late as possible, and later select the seedlings according to their flowering time. Leafing time could be used for early selection with certain success when progenitors have very different flowering times (VCTJ early and very late), since the expected variability within families will be very large., This work has been supported by the research projects AGF98-0211C03-02 and AGL2001-I054-C03-01 ("Mejora Genetica del Almendro") of the "Ministerio de Educación y Ciencia" of Spain.

8 pages, 4 tables.-- Available Online 17 Sep. 2003., Seed dormancy affects germination and subsequent seedling growth in many plant species. In this work the effect of temperature (cold and heat treatments), flowering time of genotypes, and hardness of endocarp on the break of seed dormancy in four almond cultivars, including a broad range of flowering dates, was studied. Mature seeds, with and without endocarp, were stratified at 7 °C for 1–10 weeks, followed by 5 weeks at 22 °C. The number of germinated seeds were recorded weekly for each cultivar, and cold and heat treatments. Despite the great variability observed within cultivars, a relationship between chilling requirements of cultivars for flowering and stratification requirements of seeds for germination was observed. With endocarp, stratification time required to overcome seed dormancy ranged between 6 (early flowering cultivars Desmayo Largueta and Ramillete) and 8 weeks (late-flowering cultivars Mono and Wawona) on average. Elimination of the endocarp reduced the period of stratification needed for germination in hard-shelled cultivars by 3 weeks. This effect was less important in soft-shelled almonds. No important differences between cultivars were observed for heat requirements. Two weeks at 22 °C was enough to reach the higher germination percentage after each cold treatment., This work has been financed with the project “Mejora Genética del Almendro” (AGL2001-1054-C03-01) from the “Plan Nacional de I+D” of Spanish Ministry of Science and Technology.