Cryopreservation and germinative behavior of Passiflora spp. seeds.

Cryopreservation is an interesting strategy for the long-term conservation of the seeds of the majority of cultivated plants as well as many of the corresponding wild parents. The objective of this study was to evaluate the response of the seeds of different passion fruit species to cryopreservation, as well as to apply multivariate tools to better understand the germinative behavior after thawing, to support the application and repeatability of these methods with other Passiflora species. Seeds of P. coccinea, P. edulis, P. gibertii, P. maliformis, P. morifolia, P. setacea, P. suberosa and P. tenuifila were submitted to cryopreservation, and after thawing the following variables were analyzed: emergence percentage (%); mean emergence time (days); mean emergence speed (plantlets.day-1); uncertainty (bit); and synchrony (bit). We applied multivariate analysis of variance (MANOVA) and canonical discriminant analysis (CDA) to the data. The seeds of all the species withstood the freezing well, indicating that cryopreservation is a viable alternative for long-term conservation of Passiflora genetic material. The emergence percentage, average emergence speed and average emergence time were the variables that contributed the most to separation of the species in the first canonical discriminant function (Can1). The seeds of the species studied were found to be tolerant to desiccation because they remained viable even with low water content. The results showed that seeds could be cryopreserved successfully both with and without prior desiccation.

Multivariate analysis of body morphometric traits in conjunction with performance of reproduction and milk traits in crossbred progeny of Murrah × Jafarabadi buffalo (Bubalus bubalis) in North-Eastern Brazil.

We studied the relationship between body morphometric traits, and their underlying association with milk production (MP), lactation length (LL), first calving interval (FCI) and subsequent calving interval (CI) of crossbred progeny of Murrah × Jafarabadi buffalo aiming to assist in selection programs. We carried out principal component analysis (PCA) of the body morphometric traits, which include breast width (BW), thigh width (THW), hip width (HW), rump width (RW), rump length (RL), body depth (BD), body length (BL), height withers (HEW), rear height (RH), shoulder width (SW), thorax width (TW), loin width (LW), distance from the head to ischium (DHI), and thoracic perimeter (TP). We determined the association of morphometric traits with milk/reproduction traits using canonical correlation analysis (CCA). The analysis revealed that the first six PCA accounted for 82.14% of the total observed variation, and the traits THW, HW, TW, LW, RW, HEW, TP, RH, and BW, accounted for almost half (48.00%) of the total variance indicating a higher contribution in body structural conformation. The first canonical function was significant (p<0.05), accounted for 72.46% of the total variance, and the canonical correlation was 0.56, indicating the dependence between both groups of traits. Higher canonical loadings were obtained for LL (0.49), FCI (0.46), BW (-0.71), BL (-0.56), DHI (-0.34), HEW, (-0.38) and TP (-0.50). These traits were most important for the derivation of canonical statistical variables, and presented a higher canonical correlations (r) between the dependent (LL/FCI) and independent (BW, BL, DHI, HEW and TP) groups. The results could suggest that the body morphometric traits THW, HW, TW, LW, RW, HEW, BD, TP, RH, and BW could play important role in body structural composition, indicating a suitable functional type, and aid designing of selection programs for buffalo breeding.

Multivariate analysis to evaluate genetic groups and production traits of crossbred Holstein × Zebu cows.

The objective of this research was to try to unveil the relationship between production traits and genotypic proportions of crossbred dairy cattle using principal component analysis (PCA) and cluster analysis. The herd consists of crossbred animals of Holstein (H) and Zebu (Z) (Gir and Guzerat) in different genotypic proportions; the composition of which varies from 12.5 to 100.0 % of the genetic group H. For this study, 834 milk production records from 257 cows from the years 1997 to 2014 were analyzed. The animals were all managed at a farm located in northeastern Brazil. The variables in the PCA were total milk yield per lactation (MY), milk yield adjusted to 305 days (MY305), lactation length (LL), and proportion of H and Z breeding. This analysis reduced the size of the sample space from the original five variables to two principal components (PCs) that together explained 89.4 % of the total variation. MY, MY305, LL, and genotypic proportion of H all contributed positively to PC1. The genotypic proportion of Z contributed negatively, which established a contrast between H and Z. Further cluster analysis identified two distinct groups when considering production performance and genotype of the animals. The high-performance group was predominantly Holstein breeding, while the lower performing group consisted mostly of Zebu. Under the environmental and management conditions in which this research was conducted, the best performances for the traits considered were achieved from cows whose genotypic proportion was between 38.0 and 94.0 % Holstein breeding.