Dataset Information

Ecological setup, ploidy diversity, and reproductive biology of Paspalum modestum, a promising wetland forage grass from South America.

ABSTRACT: With ever-rising demand for food, forage breeding for intensification of cattle production is also taking a leap. In South America, cattle production systems are displaced to marginal areas poorly exploited with cultivated pastures yet with high potential for growing stocking rates. This places the need for using native genetic resources to breed locally adapted plant genotypes that benefits from better forage quality, yield, and lesser threat to the local biodiversity. Paspalum modestum Mez is a grass species that produces quality forage and grows in marginal areas like estuaries and floodplains, suitable for introduction in breeding programs. In this study we characterize the species' reproductive biology and ecological preferences needed beforehand any improvement. P. modestum plants found in nature are commonly diploids, rarely triploids, and tetraploids. Chromosome associations during meiosis in polyploids indicate they are autopolyploids. While diploids are sexual self-sterile, analyses of embryology, gamete fertility and experimental crossings show tetraploids are self-compatible facultative apomicts, highly fertile and have a high proportion of sexuality compared to other apomictic species. Ecological niche analysis and species distribution modelling show mean annual temperature and precipitation as main ecological drivers and a wide geographical area of climatic suitability where P. modestum can grow and be exploited as a forage grass. Our study points to P. modestum as a native plant resource appropriate for breeding waterlogging tolerant ecotypes and genotypes of high biomass production adapted to low flow areas in the Subtropics of Brazil, Paraguay, Uruguay and Argentina.

SUBMITTER: Karunarathne P

PROVIDER: S-EPMC7198000 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Ecological setup, ploidy diversity, and reproductive biology of Paspalum modestum, a promising wetland forage grass from South America.

Karunarathne Piyal P Feduzka Cristian C Diego Hojsgaard H

Genetics and molecular biology 20200221 1 suppl 2

With ever-rising demand for food, forage breeding for intensification of cattle production is also taking a leap. In South America, cattle production systems are displaced to marginal areas poorly exploited with cultivated pastures yet with high potential for growing stocking rates. This places the need for using native genetic resources to breed locally adapted plant genotypes that benefits from better forage quality, yield, and lesser threat to the local biodiversity. Paspalum modestum Mez is ...[more]

PMID: 32110794

Similar Datasets

Project description:BACKGROUND: Paspalum (Poaceae) is an important genus of the tribe Paniceae, which includes several species of economic importance for foraging, turf and ornamental purposes, and has a complex taxonomical classification. Because of the widespread interest in several species of this genus, many accessions have been conserved in germplasm banks and distributed throughout various countries around the world, mainly for the purposes of cultivar development and cytogenetic studies. Correct identification of germplasms and quantification of their variability are necessary for the proper development of conservation and breeding programs. Evaluation of microsatellite markers in different species of Paspalum conserved in a germplasm bank allowed assessment of the genetic differences among them and assisted in their proper botanical classification. RESULTS: Seventeen new polymorphic microsatellites were developed for Paspalum atratum Swallen and Paspalum notatum Flüggé, twelve of which were transferred to 35 Paspalum species and used to evaluate their variability. Variable degrees of polymorphism were observed within the species. Based on distance-based methods and a Bayesian clustering approach, the accessions were divided into three main species groups, two of which corresponded to the previously described Plicatula and Notata Paspalum groups. In more accurate analyses of P. notatum accessions, the genetic variation that was evaluated used thirty simple sequence repeat (SSR) loci and revealed seven distinct genetic groups and a correspondence of these groups to the three botanical varieties of the species (P. notatum var. notatum, P. notatum var. saurae and P. notatum var. latiflorum). CONCLUSIONS: The molecular genetic approach employed in this study was able to distinguish many of the different taxa examined, except for species that belong to the Plicatula group, which has historically been recognized as a highly complex group. Our molecular genetic approach represents a valuable tool for species identification in the initial assessment of germplasm as well as for characterization, conservation and successful species hybridization.

Project description:Brachiaria humidicola, a tropical forage grass, is recognized for its tolerance to temporary waterlogging. Waterlogged soils are characterized by slow movement of gases and oxygen defficiency. B. humidicola accessions showed adaptations common to wetland species, including a ventilation system (aerenchyma) from shoot to root that might facilitate O2 transport and the escape of gases that usually accumulate in roots under waterlogging. Of 12 accessions tested, one accession (CIAT 26570) showed greater aerenchyma formation. Quicker growth under waterlogging of CIAT 26570 might be associated with greater aerenchyma formation. Soil waterlogging reduces gas exchange between the soil and the atmosphere, leading to oxygen deprivation in the rhizosphere. Brachiaria spp. are the most widely sown forage grasses in tropical America. Among commercial Brachiaria grasses, B. humidicola shows superior tolerance to waterlogged soils based on maintenance of growth and reduced leaf chlorophyll loss and senescence. However, little is known about the underlying traits of waterlogging tolerance in B. humidicola or their intraspecific variation. For this purpose, an outdoor study was conducted using 12 germplasm accessions of B. humidicola that were grown in soil cylinders under drained or waterlogged soil conditions for 21 days. Dry mass production and morpho-anatomical responses (aerenchyma in shoots and roots, root diameter, proportional area of stele in roots, number of nodal and lateral roots, and length of the longest root) were determined. All accessions showed shorter roots and reduced root dry mass under waterlogged soil conditions. All accessions showed aerenchyma in shoots and roots under drained conditions but were further increased under waterlogging. All accessions showed a reduction in the proportional area of stele of roots in response to waterlogging. The accession (CIAT 26570) that showed a higher proportion of aerenchyma in shoots and roots and an increased number of nodal roots (with higher diameter and a reduction in the number of lateral roots) showed longer roots, less reduction in root dry mass and increased shoot growth under waterlogged conditions. We conclude that superior growth of one accession (CIAT 26570) under waterlogged soil conditions is probably a result of morpho-anatomical traits acting together to enhance root aeration and shoot ventilation. Further research is needed to test the ability to recover from waterlogging in B. humidicola accessions.

Project description:Timothy grass (Phleum pratense L.) is one of the most important forage crops in temperate regions. Forage production, however, faces many challenges, and new cultivars adapted to a changing climate are needed. Wild populations and relatives of timothy may serve as valuable genetic resources in the breeding of improved cultivars. The aim of our study is to provide knowledge about the phenotypic diversity in domesticated (cultivars, breeding lines and landraces) and wild timothy and two closely related species, P. nodosum (lowland species) and P. alpinum, (high altitude species) to identify potential genetic resources. A total of 244 accessions of timothy and the two related species were studied for growth (plant height, fresh and dry weight) and plant development (days to stem elongation, days to booting and days to heading) in the field and in a greenhouse. We found a large diversity in development and growth between the three Phleum species, as well as between the accessions within each species. Timothy showed the highest growth, but no significant difference was found between wild accessions and cultivars of timothy in fresh and dry weight. However, these two groups of accessions showed significant differences in plant development, where timothy cultivars as a group reached flowering earlier than the wild accessions. This suggests that there has not been a strong directional selection towards increased yield during the domestication and breeding of timothy; rather, timothy has been changed for other traits such as earlier heading. Principal component analysis and cluster analysis based on all traits revealed distinct clusters. Accessions falling within the same cluster showed similarities in the development and growth rather than the type of accession. The large diversity found in this study shows the potential of using timothy accessions as genetic resources in crosses with existing cultivars. Also, accessions of P. nodosum with favorable traits can be candidates for the domestication of a novel forage crop, and the high-altitude relative P. alpinum may be a source of genes for the development of more cold and stresstolerant cultivars.

Dataset Information

Ecological setup, ploidy diversity, and reproductive biology of Paspalum modestum, a promising wetland forage grass from South America.

Publications

Ecological setup, ploidy diversity, and reproductive biology of Paspalum modestum, a promising wetland forage grass from South America.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets