Crop Adaptation in On‐Farm Management by Natural and Conscious Selection: A Case Study with Lentil

Abstract

On‐farm management of landraces or older cultivars of crop plants is often recommended to combine conservation and use of genetic resources, but experimental studies on on‐farm management are hard to find, particularly in industrialized countries. To investigate whether on‐farm management results in regional adaptation and enhances crop biodiversity, an experiment with lentils (Lens culinaris Medik.) was designed. Lentil production has almost ceased to exist in central Europe, but lentils may still be found in gene banks and have remained a popular food. Three landraces were evaluated on three farms in Germany; at each farm, three populations evolved, based on three selection methods: (i) natural selection, (ii) visual mass selection, and (iii) selection for yield of single plant progenies. These selection methods were applied for two to four years. The nine populations developed for each landrace (three methods × three locations) were grown in a comparative trial on two of the farms. In most cases, populations selected at a specific location were at this location superior in yield to populations selected at other locations, indicating that on‐farm management can result in site‐specific adaptation. Significant changes in morphological and phenological traits occurred. For one landrace, natural selection increased seed weight. The response to different selection methods largely depended on landrace and selection site, and no method was generally superior. In conclusion, on‐farm management is a useful approach to maintain, use, and develop plant genetic resources. Natural selection as the most cost‐efficient method is recommended.

Duplication assessments in Nordic Avena sativa accessions at the Canadian national genebank

“…The usefulness of intra-accession diversity in phenotypically homogeneous genebank preserved landrace accessions when re-introducing such genebank material into on-farm situations was recently demonstrated in lentil which, similar to oat, is a self-pollinating species (Horneburg and Becker 2008). Van Hintum and Knüpffer (1995) introduced the term ''common duplicates'' for accessions that trace back to the same initial population but may have altered genetic identities (allelic compositions) and they distinguish them from ''identical duplicates''.…”

Collaborative Plant Breeding for Organic Agricultural Systems in Developed Countries

“…In contrast, the particular sample of the landrace RD used for this study was composed by a farmer starting from a small number of spikes selected in accessions from the national genebank, possibly inducing a genetic bottleneck and a reduction of adaptive potential. Ex situ conservation in gene banks may lead to reduced genetic diversity due to genetic drift in small population sizes [9,36]. The lack of response to selection in Renan is not surprising as we expected the observed selection differential to be due primarily to micro-environmental factors that led to phenotypic differences among plants within a single plot in the selection generation.…”

“…This reduces the need for genetic diversity in commercial varieties [3] but these varieties are only superior in a narrow range of production environments where growing conditions are standardized and stress is minimized [4]. Many authors have pointed to a need for greater diversity in agriculture [1,3,[5][6][7][8][9][10][11][12]. Due to greater heterogeneity of environmental conditions (both spatial and temporal) in organic systems, there is a particular need to increase genetic diversity on organic farms [13][14][15][16][17][18].…”

Pure-lining of flax (Linum usitatissimum L.) genebank accessions for efficiently exploiting and assessing seed character diversity

“…Horneburg and Becker (2008) recently demonstrated in the self-pollinating lentil how important intra-accessions diversity of genebank accessions can be when re-introducing such material into on farm situations, because it increases the adaptive potential. Table 4 provides an overview of the different priorities that exist in sectors working with flax germplasm and the implication regarding pure-lining or accession separation.…”

“…The price for establishing a collection of genetically homogenous accessions, i.e. pure lines, is the possible loss of intra-accession diversity, which is one characteristic of landraces and ensures adaptability to changing environmental conditions and yield stability of these landraces (Zeven 1998;Horneburg and Becker 2008). The concern to lose diversity combined with the economic pressure on genebanks has also resulted in suggestions to combine flax genebank accessions that had no or only little phenotypic or molecular differences .…”