Mode of reproduction and amplified fragment length polymorphism variation in purple needlegrass (Nassella pulchra): utilization of natural germplasm sources

Abstract

A dominant plant of the California grasslands, purple needlegrass [Nassella pulchra (Hitchc.) Barkworth] is an important revegetation species in its native range. The amplified fragment length polymorphism (AFLP) method was used to elucidate mode of reproduction and nucleotide variation among 11 natural populations and three selected natural germplasm releases of N. pulchra. A total of 12 co-dominant AFLPs, informative within eight populations, failed to reveal any heterozygous individuals, indicating very high selfing rates (S(H)=1). Estimates of nucleotide diversity within populations ranged from 0 to 0.00069 (0.00035 average), whereas the total nucleotide divergence among populations ranged from 0.00107 to 0.00382 (0.00247 average). Measures of population differentiation (GS) in terms of Shannon-Weaver diversity values and estimated nucleotide substitutions were 0.90 and 0.86, respectively. Although some of the sample populations contained a mixture of true breeding genotypes, most populations could be distinguished unambiguously. Moreover, geographical distance between the natural source populations was significantly correlated with genetic distance (r = 0.60) among the corresponding sample populations. Results indicate that inbreeding, combined with founder effects and/or selection, has contributed to the differentiation of N. pulchra populations. Foundation seed populations of the selected natural germplasm releases were genetically well defined and most similar to natural seed collected near the corresponding source populations. Thus, these commercial germplasm sources will be made practically available and useful for conservation plantings within the intended areas of utilization.

Genetic and morphological differentiation between Melica ciliata L. and M. transsilvanica Schur (Poaceae) in Europe reveals the non-presence of M. ciliata in the Polish flora

“…Moreover, our findings are congruent with those of previous allozyme study [7] showing that the proportion of the genetic diversity that resides between populations (G ST = 0.53) was far higher than reported for most diploid plants and were only comparable with the mean G ST reported for obligatory selfing species [78]. For example, a large reduction of genetic variability within populations and increased differentiation between populations have been observed in obligatory selfing grass Bromus tectorum [80] or in predominantly selfing grass Nassella pulchra [81] and in wetland species Typha latifolia [82].…”

Low level of genetic variation within Melica transsilvanica populations from the Kraków-Częstochowa Upland and the Pieniny Mts revealed by AFLPs analysis

“…Large reductions in genetic variability within populations and increased differentiation among populations have also been observed in other self-fertilizing grasses (Price et al 1984;Larson et al 2001). Genetic diversity of Melica transsilvanica is lower than that found in other facultative self-pollinating grass species, e.g.…”

“…AFLP markers were found useful in estimating microgeographic isolation by distance between populations (Hardy 2003). It is a very effective method of investigating closely related taxa characterized by a low level of genetic diversity (OHanlon et al 2000), and has also been used to elucidate the mode of reproduction (Larson et al 2001). …”

Genetic diversity of fringed brome (Bromus ciliatus) as determined by amplified fragment length polymorphism

“…J. Bot. 83: 1322-1328 (2005) doi: 10.1139/b05-112 2005 NRC Canada cern has its roots not only in adaptation but also in genetic diversity, as general knowledge about genetic diversity of many grass species native to North America is largely lacking (Huff et al 1998;Larson et al 2001a;Fu et al 2004&). Little attention has been paid to assess the genetic diversity of native grass species, particularly using molecular techniques, for the development of diverse grass germplasm with improved seed production.…”