Unpredicted persistence of all forms of B. napus present in the agro-ecosystem is the most common consequence of preservation and self-recruitment of seeds originating from soil seed bank. In nature, spontaneous intra- and inter-specific hybridization of B. napus is possible with sexually compatible species from the Brassicaceae family. The aim of this chapter is (a) to identify the distribution pattern and population dynamics of volunteers and feral populations along statistical regions in Slovenia; (b) to assess the global diversity of naturally appearing B. napus plants; (c) to evaluate the genetic differentiation between volunteers and feral populations; (d) to obtain the spatial and temporal distribution of spontaneous pollination potential and estimation of gene flow conservation; (e) to find the empirically assigned out-crossing rate of B. napus under a fragmented landscape structure, during 4-year monitoring; and (f) to observe that ecologically, evolutionary, and agronomically oriented studies could be conducted at the DNA level using short sequence repeat (SSR) markers. In total, we collected 261 samples of volunteer and feral populations. Our results showed that alleles from both volunteer and feral populations were distributed in three genetic clusters with relatively similar levels of diversity. Naturally occurring out-crossing rate is 13.71%. The global Mantel correlation coefficient of genetic and spatial relatedness between genotypes is 0.044.
Part of the book: Brassica Germplasm
Drought is one of the major threats to common bean (Phaseolus vulgaris L.), affecting its growth and productivity and, thus, contributing to considerable losses in yield in many regions worldwide. The development of varieties tolerant of drought stress has, therefore, become one of the primary goals in many common bean breeding programs. Plants have developed various mechanisms of their adaptation, to a greater or lesser extent, to drought. These are expressed, on the molecular level, by changes of gene expression and of protein content, together with responses at physiological and morphological levels. The response of common bean to drought is still not sufficiently well characterized due to its genetic complexity and its diverse, often ambiguous, phenotypic effects. Understanding these mechanisms is thus of fundamental importance for developing varieties that are better adapted to such stress conditions. In this chapter, we present research that provides an insight into the morpho-physiological adaptation and its underlying molecular changes in common bean plants exposed to drought. We include our contribution to establishing the basis for breeding of common bean with greater tolerance to this abiotic stress that uses molecular markers and identification of quantitative trait loci (QTLs).
Part of the book: Drought