Évaluation agronomique de variétés de pays de sainfoin (Onobrychis sativa L) originaires du sud-est de la France

Abstract

production under open-field pollination. An analysis of variance of these traits revealed the superiority of cultivar Fakir for vegetative and seed production. The local varieties showed a better winter growth, a quick start in the spring and a earlier flowering time while keeping a good level of frost tolerance. This is a very interesting trait for the farming systems in these regions, because it allows grazing during the winter which is complementary to the alfalfa cultivars used. Sainfoin shows a large variability for aftermath flowering. The differences between the 2 types of growth, '1 cut' and '2 cuts', are highly significant. The '1 cut' local varieties are less productive and show a low persistency. This is the contrary of what is generally observed by farmers. This could be due to the frequency of cutting (3-4 cuts during the growing season) which is the normal rate for the 2 cuts' types. In these regions '1 cut' local vari-* Correspondance et tirés à part eties are usually grazed in spring and autumn, with a rest period during the summer. Principal component analysis was carried out to identify clusters of homogeneous behaviour. Firstly, there is a definite separation between the '1 cut' and '2 cuts' types and between the cultivars and local varieties. This confirms the originality of these local varieties. A hierarchical clustering method on the first 4 components was used to separate the different groups. A partition into 6 clusters was chosen. Each cluster was described by means of the different traits and compared with the other clusters. The genetic resources of sainfoin are very difficult to preserve, because this species is allogamous, self-incompatible, requires insect pollination, and its seeds have a low viability (5-8 years), even in a cold chamber. These clusters were used to build some 'genetic pools' to preserve the local varieties collected.

The agronomic variability of a collection of sainfoin accessions

“…The strong correlation seen between percentage flowering in the sowing year and the capacity of summer regrowth after the cut is one of the characteristics that differentiated the giant sainfoins. This greater regrowth capacity has been reported in other studies (Thonson, 1951, cited by Michelena, 1983Michelena and Hycka, 1988;Prosperi et al, 1994). In the present study it was sig- …”

“…The capacity to flower in the sowing year has been the main criterion used for classifying accessions as common or giant sainfoin (Michelena and Hycka, 1988;Prosperi et al, 1994). In the present study, the differences between accessions in terms of mean percentage flowering in the sowing year were significant (P < 0.001).…”

“…However, if this characteristic is considered in isolation it becomes difficult to assign many accessions to either the common or giant group since percentage flowering can be close to 50%, and varied according to the location of the trial. The giant Fakir cultivar (accession number 41), which was used as a control in these trials because of its phenological homogeneity (Prosperi et al, 1994), helped in the assessment of the heterogeneity of the accessions. In the irrigated trial, 100% of the plants flowered; however, on the rainfed land only 73% did so.…”

“…Autumn and summer regrowth, plus winter growth related to vigour and the growth habit have been used in a complementary fashion in the differentiation of the two types of sainfoin by other authors (Michelena and Hycka, 1988;Prosperi et al, 1994). The strong correlation seen between percentage flowering in the sowing year and the capacity of summer regrowth after the cut is one of the characteristics that differentiated the giant sainfoins.…”

“…The capacity for summer regrowth 20 days after the first cut was also measured visually in 2004 (using the same 1 to 9 scale). These important, easy-to-measure variables have been recorded in different studies on the characterization of local sainfoin ecotypes (Michelena and Hycka, 1988;Prosperi et al, 1994) and alfalfa (Medicago sativa L.) (Hidalgo, 1966;Delgado, 1986).…”