A rapid method to increase the number of F1 plants in pea (Pisum sativum) breeding programs.

In breeding programs, a large number of F2 individuals are required to perform the selection process properly, but often few such plants are available. In order to obtain more F2 seeds, it is necessary to multiply the F1 plants. We developed a rapid, efficient and reproducible protocol for in vitro shoot regeneration and rooting of seeds using 6-benzylaminopurine. To optimize shoot regeneration, basic medium contained Murashige and Skoog (MS) salts with or without B5 Gamborg vitamins and different concentrations of 6-benzylaminopurine (25, 50 and 75 µM) using five genotypes. We found that modified MS (B5 vitamins + 25 µM 6-benzylaminopurine) is suitable for in vitro shoot regeneration of pea. Thirty-eight hybrid combinations were transferred onto selected medium to produce shoots that were used for root induction on MS medium supplemented with α-naphthalene-acetic acid. Elongated shoots were developed from all hybrid genotypes. This procedure can be used in pea breeding programs and will allow working with a large number of plants even when the F1 plants produce few seeds.

Diversity of pea (Pisum sativum) accessions based on morphological data for sustainable field pea breeding in Argentina.

We characterized 13 accessions of dry peas of different origins from various growing regions in Argentina, based on three replications of 20 plants cultivated in 2009 and 2010 in a greenhouse, with the objective of selecting those with favorable characteristics for use in breeding programs. Significant differences were found for length and width of stipule and pod, length of the internodes and leaflets, plant height, total number of nodes, number of nodes at the first pod, number of days to flowering and to harvest, number of pods and seeds per pod, 100-seed weight and grain diameter, demonstrating a high degree of genetic variability. Phenotypic correlation analysis demonstrated that large pods produced more seeds per pod, but the seed weight decreased. Plants with smaller number of nodes in the first pod were more productive. Estimates of genotypic correlation coefficients indicated a strong inherent association among the different traits. Clustering methods grouped the accessions into five clusters. Cluster 5 included two accessions and showed the highest values for length and width of stipules (4.9 and 4.5 cm, respectively), length of leaflets (7.43 cm) and days to flowering (122.6), while cluster 3, with one accession, and cluster 4, with two accessions, showed the highest values for number of seeds per pod (3.78 and 4.39), number of pods per plant (5.33 and 5.70), length of pods (5.54 and 5.72 cm), and width of pods (1.21 and 1.20 cm, respectively). We conclude that accessions in clusters 3 and 4 would be useful for crosses with other cultivars in pea breeding programs.

[Women and breast feeding: understanding their experiences and analyzing the performance of the health system]. / Mujeres y lactancia: entendiendo sus vivencias y analizando la actuación del sistema sanitario.

OBJECTIVE: To understand the conditioning factors which, whether negatively or positively, affect the success or failure of breast-feeding and to analyse the intervention of the health system to support it. DESIGN: A descriptive, prospective study which uses qualitative methodology in data gathering and analysis. SETTING: Health District of Santa Perpetua de la Mogoda, Barcelona. PARTICIPANTS: 56 in-depth interviews of 20 women were carried out at different moments of the pregnancy and suckling. MEASUREMENTS AND MAIN RESULTS: The decision to breast-feed was taken by women before or during their pregnancy under the influence of their social and family environment. The performance of the health system had little influence on the decision. The birth, even if it was pathological, did not prevent breast-feeding except when it was experienced as a failure. The days before the milk came increased women's insecurity about their capacity to suckle. Information from hospitals was evaluated as being scant. Fear of not feeding the baby well was the major source of breast-feeding failure. Mothers who breast-fed for longer felt they received more sympathy from paediatricians than those who gave up early. These felt blamed and did not seek doctors' advice on their decision. CONCLUSIONS: The health system has to plan an efficient intervention to support breast-feeding in the most crucial moments: after the birth and on arriving home.