Prospection and collection of species of interest for livestock production in two Cuban provinces
Odalys C. Toral1, Marlen Navarro1 and J. Reino1
1Estación Experimental de Pastos y Forrajes Indio Hatuey,
Universidad de Matanzas, Ministerio de Educación Superior. Central España Republicana, CP 44280, Matanzas, Cuba
A mission of prospection was carried out in Las Tunas and Camagüey provinces, in order to collect samples of herbaceous, shrub and tree species of multipurpose use in the livestock production sector, to create a germplasm bank. When abundant population was found a random sampling method was used, and in small populations individual sampling was made, in which species were repeated in different sites. The information was gathered through several descriptors related to the location, natural habitat, vegetation, soil and damage caused by insects and microorganisms. In the prospected zones a high genus and species diversity was concentrated, for the accessions of herbaceous type (17 genera with 23 species) as well as for the tree and shrub accessions (13 genera with 15 species). A total of 55 accessions of 38 herbaceous and 17 shrub and/or tree species were collected. The highest diversity of species was found on the soils of the Brown and Fersialitic groupings, which are more fertile and show better permeability. Species that have been used with diverse purposes were collected, belonging to the genera: Teramnus, Lablab, Cynodon, Clitoria, Canavalia, Centrosema and Leucaena; as well as new materials (Sesbania sp. and Cassia sp.) which could be used as living fence, cover plants and green manure. It is considered that the collection provides a material with excellent multiuse perspectives in the livestock production sector, and contributes to the increase of the existing germplasm reserve with naturalized ecotypes.
Keywords: Germplasm, legumes, plant collection.
The plant genetic resources for food and agriculture (PGRFA) comprise the fraction of biological diversity that includes the plant species with current or potential value, and provide the raw material for diverse studies related to the breeding programs and to livestock production sustainability. These resources are basic to increase the productivity and sustainability of livestock production, and contribute to the development of nations; the world food security and the decrease of poverty depend on them (FAO, 2001).
On the other hand, it is important to emphasize that the problem of genetic erosion is aggravated with the disappearance of species and wild forms of cultivated plants, because of such processes as massive deforestation or the degradation and contamination of natural habitats, which are the result of the abusive exploitation of the resources of the planet.
The loss of genetic variability supposes the limitation of the capacity of response to the new needs, as well as the increase of the vulnerability of crops to environmental changes or to the emergence of new pests and diseases.
The above-explained facts show the importance of the prospection and collection of native and/or naturalized materials, in order to rescue these resources and other species of interest. In addition, it is necessary to enrich the germplasm with new national acquisitions and to evaluate their forage potential (Toral et al., 2003); as well as to improve the genetic basis of pastures and forages (Olivera et al., 2003) and to promote forage areas, from varieties identified in this activity (Oquendo et al., 2013).
The objective of this research was to collect samples of herbaceous, shrub and tree species of multipurpose use in the livestock production sector, from a prospection mission in Las Tunas and Camagüey provinces _Cuba_, to create a germplasm bank.
MATERIALS AND METHODS
Region of collection. The collection mission was carried out in zones belonging to Las Tunas and Camagüey provinces, for which some basic principles exposed in the methodology for the collection, conservation and characterization of herbaceous, tree and shrub species useful for livestock production (Machado et al., 1999) were taken into consideration. In this sense, a map with scale 1:1 000 000 (ACC, 1998), in which the existing populations and soil groupings were indicated, was taken as reference.
In the sampling priority was given to the sites located in marginal areas, with diversity of lands (flat, undulated and mountainous), deep roadsides with scrubland vegetation (soil covered by diverse types of plants, including natural and naturalized pastures), clearings, limiting fences of naturalized _or not naturalized_ pastures and other crops, hills and perimeter forest areas, as well as thickets and disturbed woodland.
The samples were collected on soils of the genetic groupings Brown and Fersialitic, which showed moderate to high fertility, with organic matter content between 3 and 9 %.
Sampling method and descriptors. For most species an individual sampling method was used, because, regularly, the seeds were taken from small populations. A random sampling was also used, when a high number of individuals of a certain species was encountered. From each plant the highest quantity of samples was collected, and the species were repeated in the places where it was possible, so that higher variability was achieved. The species considered useful were sampled, independently from their vigor, but those which showed severe damage caused by pests and/or diseases were avoided.
In the autogamous species, the seed collected from each plant was maintained separated; and in the case of trees, the collection was made in the highest possible quantity of individuals, in order to maximize the heterosis of the material from allogamous plants.
The propagules were kept wrapped in moist newspaper, to prevent their desiccation during the collection period. The seeds were maintained in paper envelopes, conveniently identified, separated and sealed, to avoid the contamination of their contents.
Afterwards, the collected germplasm was transported to the Pastures and Forages Research Station Indio Hatuey _Matanzas, Cuba_ in order to make the corresponding bank, for which a nursery was previously created.
Besides the sample number, several descriptors were used (location, natural habitat and vegetation of the area, specific site, soil and damage caused by phytophagous insects and pathogen microorganisms) related to the general information, which was recorded in forms elaborated for that purpose.
The distance between a collection site and the next depended on the changes in the landscape and the soil, and on the simple visualization of the plants. In each collection site an area of approximately 1,0 ha was traveled, in all directions, when the natural obstacles allowed it.
RESULTS AND DISCUSSION
In the collection areas a high genus and species diversity was concentrated (table 1), for the herbaceous (17 genera with 23 species) as well as for the tree and shrub accessions (13 genera with 15 species). It is important to emphasize that the most adequate date for the collection of herbaceous species does not always coincide with the most opportune moment to find woody plants with seeds, aspect implicit in the methodology for the collection of useful germplasm for livestock production (Machado et al., 1999). This indicates that for certain environments and species seeds can be found, although the collection does not coincide with the phenological patterns that regulate the reproductive period for species with different habits, because it can depend on the specific patterns imposed by the climate and edaphic variables, aspect to which attention should be paid.
Such results could be associated to the excellent possibilities of legumes to grow in wild ecosystems, in which neither agrochemicals nor other inputs are used. Hernández et al. (1999) stated that most of the species collected in several livestock production regions, under low or no fertilization conditions, were legumes. This is due to their scarce possibilities _depending on their physiological characteristics_ of living together with grasses and other plants in fertilized areas, which is highly important when conceiving the current and future livestock production systems without irrigation and fertilization.
At present there are important species and commercial varieties of legumes which are product of the collection, and have turned out to be potentially useful for different purposes in commercial livestock production. Such is the case of Albizia lebbeck, Bauhinia purpurea and Leucaena leucocephala, among the woody types (Simón et al., 1998; Hernández, 2000); while in the herbaceous types Centrosema molle and Teramnus labialis have stood out (Paretas et al., 1989). For such reason, the collected material of these taxa is extremely interesting, because it contains specific genetic information for the particular environments where they were found, which differ from other ecosystems (Toral et al., 2001). Of this material, Desmodium sp., Galactia sp. and Cannavalia ensiformis could be used as cover plants and green manure; and Cassia biflora, for living fence and green manure.
From the 38 collected species, 47 % was found on soils of the Fersialitic grouping and 53 % on Brown soils (table 2), which had excellent to regular external and internal drainage and low to acceptable fertility, respectively. It is considered that the soil conditions and the climate indicators in these regions propitiated a high presence of herbaceous and shrub legumes, which corroborates the report by Álvarez et al. (2001).
Table 3 shows that most of the collected species were found in areas of flat topography; only four accessions, belonging to the species Desmodium sp.(1), Centrosema sp. (2), Canavalia sp. (1) and Ateleia cubensis (1), were located in mountainous areas with great natural elevation, in the Camagüey province.
In addition, it could be observed that the species were mixed, to a higher or lesser extent, with scrub vegetation, pastures and shrubs-trees, which presupposes the high level of associative ability shown by these species (particularly the herbaceous ones) with regards to those that achieve high growth and development, as in the case of shrub and tree types, and the grasses of different habits, which are characteristic of this vegetation.
On the other hand, it was interesting that none of the collected species showed affectations caused by insects or diseases.
With the exception of nine accessions, of the species Centrosema plumieri (1), Bauhinia sp. (1), A. lebbeck (1), C. biflora (1), Centrosema pubescens (1), Phaseolus lunatus (1), Sesbania sesban (1), Crotalaria sp. (1) and S. glandiflora (1), which were found in areas where the soil was completely uncovered by vegetation, the others were located on a surface with certain degree of cover, which was classified into slight, moderate and abundant. This is propitious for the implementation of silvopastoral systems, in which there should be a first plant stratum, mainly formed by grasses and/or herbaceous legumes, and was corroborated for A. lebbeck, G. sepium and L. leucocephala by Simón et al. (1998), and for A. lebbeck by Pentón (2000). The degree of shade received by such accessions varied between soft or none, and the herbaceous plants as well as the trees tended to be heliophilous.
It is concluded that the collection provided a material with excellent multiuse perspectives in the livestock production sector, and in turn contributes to the increase of the existing germplasm reserve with naturalized ecotypes.
Received: January 10, 2015
Accepted: February 3, 2015