The genetic diversity of “Gama” and “Bico de Corvo”, local cultivars of olive tree (Olea europaea) from seven traditional orchards of Ficalho (Alentejo region, Portugal), was studied to characterize the local diversity and assess the level of on farm diversity. Two different analytical systems were used: endocarp morphological characteristics and genetic analysis by microsatellite markers (Simple Sequence Repeats or SSR). The seven screened loci were polymorphic and allowed the identification of 23 distinct SSR profiles within the 27 trees analyzed. A total of 52 different alleles were scored, with an average of 7.43 alleles/SSR locus, and considerable genetic diversity was found. Neighbor-Joining algorithm cluster analysis and principal co-ordinate analysis (PCoA) allowed for the identification of the genetic relationships between several accessions. The 27 Olea accessions were clearly separated into three different groups. SSR analysis was more precise than endocarp characterization in the classification of genetic diversity among the olive tree cultivars. The study shows reasonable olive tree diversity in Ficalho, indicating that these traditional orchards are important reservoirs of old minor cultivars and incubators of new genotypes.

Pine wilt disease (PWD) caused by pine wood nematode (PWN), Bursaphelenchus xylophilus, is a serious threat to global forest populations of conifers, in particular Pinus spp. Recently, the presence of PWN was reported in dead Yunnan pine (Pinus yunnanensis) trees under natural conditions. To further understand the potential impact caused by PWN in Yunnan pine populations, a transcriptional profiling analysis was performed over different time points (0 hours (h), 6 h, 24 h, 48 h, and 7 days) after PWN inoculation. A total of 9961 differentially expressed genes were identified after inoculation, which suggested a dynamic response against the pathogen, with a more intense pattern at 48 h after inoculation. The results also highlighted a set of biological mechanisms triggered after inoculation that provide valuable information regarding the response of Yunnan pine to PWN infection. When compared with maritime pine (Pinus pinaster), the Yunnan pine response was less complex and involved a smaller number of differentially expressed genes, which may be associated with the increased degree of resistance to PWN displayed by Yunnan pine. These results revealed different strategies to cope with PWN infection by these two pine species, which display contrasting degrees of susceptibility, especially in the timely perception of the infection and response magnitude.

A rich heritage of traditional pear varieties is kept in national Portuguese collections. Out of these varieties, “Rocha” dominates national pear production. Although a noticeable phenotypic variation among clones of this variety has been reported, little is known about its genetic variability, as to date molecular studies have been performed on a single “Rocha” clone. Eleven Simple Sequence Repeats (SSR) markers were used to assess the genetic diversity of 130 local cultivars, 80 of them being “Rocha” clones. The results allowed the differentiation of 75 genotypes of which 29 are “Rocha”. Three synonyms groups and four homonymous groups of other local varieties were confirmed. A Bayesian model-based clustering approach identified two distinct clusters. Using flow cytometry, six cultivars were found to be triploids. These results show high genetic variability among “Rocha” clones. In conclusion, there is a need for different “Rocha” clones to be preserved to enable the correct selection of the multiplication material.

In this work, using simple sequence repeat (SSR) markers, we present new insights into the genetic diversity, differentiation, and structure of Beta vulgaris subsp. maritima of western Iberia and the Azores and Madeira islands and of B. macrocarpa from southern Portugal. B. macrocarpa occurs only in southern Portugal and frequently in sympatry with B. vulgaris subsp. maritima, showing genetic introgression. B. macrocarpa has a better-defined structure than B. vulgaris subsp. maritima, which has a high degree of admixture. A great differentiation (F_ST ranging from 0.277 to 0.184) was observed among the northern populations of B. vulgaris subsp. maritima. In contrast, only a small differentiation (F_ST ranging from 0.000 to 0.026) was detected among the southern B. vulgaris subsp. maritima populations. The inland B. vulgaris subsp. maritima populations (“RIO” and “VMT”) are distinct from each other, which also occurs with the two islands’ populations (“MAD” and “AZO”). The existence of two distinct Atlantic Sea currents can explain the fact that Madeira is related to the southern populations, while the Azores is related to the northern populations. We consider that understanding the relationships existing within Beta spp. is key to future genetic studies and for the establishment of conservation measures. Our results show that the southern coastal areas of Portugal should be considered as a potential site for in situ conservation of the beet wild relatives. Special attention is needed in what concerns B. macrocarpa because this is a rare species that also occurs in a sympatric relationship with B. vulgaris subsp. maritima.

Cowpea (Vigna unguiculata (L.) Walp.) is currently a legume crop of minor importance in Europe but a highly relevant staple crop in Africa and the second most cultivated legume in Mozambique. In Portugal and Mozambique, cowpea’s phenotypic and genetic variation has been maintained locally by farmers in some areas. We used the molecular markers SSR, SilicoDArT and SNP to analyze the genetic diversity and population structure of 97 cowpea accessions, mainly from Portugal (Southern Europe) and Mozambique (Southern Africa). As far as we know, this is the first time that the genetic variation and the relationship between cowpea landraces collected in Portugal with those originated in Mozambique is reported. Despite the shared historical past, the Portuguese landraces did not share a common genetic background with those from Mozambique, and two different gene pools were revealed. Knowledge of the genetic structure of cowpea landraces offers an opportunity for individual selection within landraces adapted to particular eco-physiological conditions and suggests the existence of a valuable gene pool for exploitation in future Portugal-PALOP (Portuguese-speaking African countries) cowpea breeding programs.

Portugal contributed to the global diffusion of sweetpotato (Ipomoea batatas L. Lam.). Although it is of minor importance on the Portuguese mainland, it is one of the most common crops in the Azores and Madeira archipelagos and is highly relevant in the Portuguese ex-colonies Mozambique and Timor-Leste. We analyzed the genetic diversity and population structure of sweetpotato from these five geographic provenances using twelve nuclear simple sequence repeat (SSR) markers. We studied 45 accessions, 15 of which were collected from farmers’ fields in these five regions and 30 of which are held at “Banco de Germoplasma de Moçambique”. The SSR markers showed a high level of polymorphism and a high number of alleles per locus. Population structure analyses using Bayesian clustering (STRUCTURE) grouped accessions from farmers’ fields into two groups and divided samples of “Banco de Germoplasma de Moçambique” into three groups. A principal coordinate analysis (PCoA), based on the Bruvo distance, supported the population structure analysis. Concerning the genebank accessions, the two analyses indicated three clusters, all of them containing Mozambican landraces. From our results, it may be concluded that sweetpotato populations from the three countries do not share a common genetic background, despite the shared history of the countries.