A genetic linkage map of tef [Eragrostis tef (Zucc.) Trotter] based on amplified fragment length polymorphism

A genetic linkage map of tef was constructed with amplified fragment length polymorphism (AFLP) markers using F₅ recombinant inbred lines (RILs) derived by single seed descent from the intraspecific cross of ’Kaye Murri’×’Fesho’. A total of 192 EcoRI/MseI primer combinations were screened for parental polymorphism. Around three polymorphic fragments per primer combination were detected, indicating a low polymorphism level in tef. Fifty primer combinations were selected to assay the mapping population, and 226 loci segregated among 85 F₅ RILs. Most AFLP loci behaved as dominant markers (presence or absence of a band), but about 15% of the loci were codominant. Significant deviations from the expected Mendelian segregation ratio were observed for 26 loci. The genetic linkage map comprised 211 markers assembled into 25 linkage groups and covered 2,149 cM of genome. AFLP is an efficient marker system for mapping plant species with low polymorphism such as tef. This is the first genetic linkage map constructed for tef. It will facilitate the mapping of genes controlling agronomically important traits and cultivar improvement in tef. Received: 27 April 1998 / Accepted: 4 January 1999     

Desiccation tolerant ‘resurrection’ grasses from Kenya and West Africa

Summary Only a very small proportion of angiospermae have foliage which can recover (within 24 h) from full airdryness. The number of such plants was extended by five grass species, in the genera Eragrostis, Sporobolus and Tripagon, and by two sedges, Kyllinga spp. The basal leaf meristematic zones in most species survived equilibration to air of 0 to 5% RH, whereas mature leaf tissue in most survived 5 to 30% RH.     

C4 acid decarboxylation type in Eragrostis (Poaceae) patterns of variation in chloroplast position, ultrastructure and geographical distribution

Abstract We investigated the activity of C₄ acid decarboxylating enzymes, the PCR (‘photosynthetic carbon reduction’, or ‘Kranz’) bundle sheath anatomy and ultrastructure, and the geographical distribution of Australian species of the C₄ grass genus Eragrostis. Species had either the even sheath outline and centripetally located PCR cell chloroplasts characteristic of NAD-malic enzyme (NAD-ME) species (29 spp.), the uneven sheath outline and centrifugal PCR cell chloroplasts characteristic of PEP carboxykinase (PCK) species (28 spp.), or were intermediate between these types (7 spp.). The suberized lamella was present in PCR cell walls of species with PCK-like and intermediate anatomy, and absent from those of species with NAD-ME-like anatomy. Biochemical determination of C₄ type for 11 species, however, revealed only NAD-ME activity, irrespective of anatomical type; no PCK activity was detected. PCK-like species arc most numerous in northern, high rainfall, tropical Australia and also predominate in relatively humid coastal and subcoastal areas. NAD-ME-like species are numerically and proportionally dominant where rainfall is < 30 cm year^?1. Overall, as many species occur in high as in low rainfall areas. Results are discussed in relation to previously established anatomical/ultrastructural/geographical/biochemical correlations and to Infrageneric taxonomy.     

Impacts of introduced grasses on breeding season habitat use by northern bobwhite in the South Texas plains

Introduced grasses may affect diversity of native fauna and flora adversely, and disrupt ecosystem processes. Many rangelands in South Texas have been seeded to or have been colonized by buffelgrass (Pennisetum ciliare) and Lehmann lovegrass (Eragrostis lehmanniana), perennial bunchgrasses native to Africa. The objective of this research was to quantify impacts that these 2 species of introduced grasses may have on northern bobwhite (Colinus virginianus) habitat use on South Texas rangelands during the breeding period (Apr–Aug). We evaluated the effects of buffelgrass and Lehmann lovegrass on northern bobwhite nest habitat (n = 35 nests) and general habitat use sites (n = 86 radiomarked quail) with logistic regression and habitat selection functions based on simple saddlepoint approximations. Buffelgrass was used as a nesting substrate at 11% of nests; however, vegetation height and visual obstruction between 1 cm and 30 cm were the best predictors of nest site use. Areas of introduced grass coverage ≥15–20% were avoided by northern bobwhites at general habitat use organism-centered points, but not at nest site use points. Introduced grass coverage and forb coverage were the best predictors of general habitat use, and bobwhites avoided areas with ≥18% introduced grass cover. These results suggest that avoidance of areas with extensive introduced grass cover may indicate a reduction in usable habitat space for northern bobwhite in the western South Texas plains. Maintaining native grass stands while implementing localized control of introduced grasses could be used as a strategy to promote habitat for northern bobwhites. © 2011 The Wildlife Society.