Leaf Length Variation in Perennial Forage Grasses

Abstract

Leaf length is a key factor in the economic value of different grass species and cultivars in forage production. It is also important for the survival of individual plants within a sward. The objective of this paper is to discuss the basis of within-species variation in leaf length. Selection for leaf length has been highly efficient, with moderate to high narrow sense heritability. Nevertheless, the genetic regulation of leaf length is complex because it involves many genes with small individual effects. This could explain the low stability of QTL found in different studies. Leaf length has a strong response to environmental conditions. However, when significant genotype × environment interactions have been identified, their effects have been smaller than the main effects. Recent modelling-based research suggests that many of the reported environmental effects on leaf length and genotype × environment interactions could be biased. Indeed, it has been shown that leaf length is an emergent property strongly affected by the architectural state of the plant during significant periods prior to leaf emergence. This approach could lead to improved understanding of the factors affecting leaf length, as well as better estimates of the main genetic effects.

Defoliation Strategies in Pastures Submitted to Intermittent Stocking Method: Underlying Mechanisms Buffering Forage Accumulation over a Range of Grazing Heights

“…5). According to Da Silva et al (2015), abiotic factors such as light and temperature affect morphogenetic processes of forage plants, so that all processes involved in plant growth and development are reduced when they are deprived of these factors (Barrett et al, 2005;Barre et al, 2015;Gastal and Lemaire, 2015). Although four structurally and morphologically distinct pasture canopies were created, Parsons et al (1988a) theoretically proposed that it was possible to accumulate a similar forage amount in pastures subjected to different defoliation strategies under intermittent stocking.…”

Acúmulo De Forragem Durante O Período De Ocupação Dos Animais Em Pastos Sob Lotação Intermitente

“…Adicionalmente, variáveis ligadas à lâmina foliar (e.g. taxa de alongamento e comprimento) são as mais importantes na determinação do acúmulo de forragem de pastos em estádio vegetativo (18) .…”

A Conserved Potential Development Framework Applies to Shoots of Legume Species with Contrasting Morphogenetic Strategies

“…Overall, organogenetic and expansive growth characteristics define and—by their ongoing interactions constrain—the shoot morphogenesis of any particular plant genotype. Trade-offs very often occur (e.g., in grasses between leaf growth and tillering; Nelson, 2000; Barre et al, 2015), which therefore makes it worthwhile analysing these two aspects of morphogenesis together.…”