Serendipitous In Situ Conservation of Faba Bean Landraces in Tunisia: A Case Study

Elyes Babay,Wilma Sabetta,Giacomo Mangini,Khalil Khamassi,Domenico Pignone,Cinzia Montemurro,Monica Marilena Miazzi,Mariella Matilde Finetti-Sialer,Donatella Danzi

doi:10.3390/genes11020236

Abstract

Cultivation of faba bean (Vicia faba L.) in Tunisia is largely based on improved varieties of the crop. However, a few farmers continue to produce local cultivars or landraces. The National Gene Bank of Tunisia (NGBT) recently launched a collection project for faba bean landraces, with special focus on the regions of the North West, traditionally devoted to cultivating grain legumes, and where around 80% of the total national faba bean cultivation area is located. The seed phenotypic features of the collected samples were studied, and the genetic diversity and population structure analyzed using simple sequence repeat markers. The genetic constitution of the present samples was compared to that of faba bean samples collected by teams of the International Center for Agricultural Research in the Dry Areas (ICARDA) in the 1970s in the same region, and stored at the ICARDA gene bank. The results of the diversity analysis demonstrate that the recently collected samples and those stored at ICARDA largely overlap, thus demonstrating that over the past 50 years, little genetic change has occurred to the local faba bean populations examined. These findings suggest that farmers serendipitously applied international best practices for in situ conservation of agricultural crops.

Highlights

Faba bean (Vicia faba L., 2n = 2x = 12) is a facultative cross-pollinating species with outcrossing rates varying between 1 and 55% depending on its environment; it belongs to the Fabaceae family, Faboideae subfamily, tribe of Fabeae, and is not interfertile with any other Vicia species [1]
Morphometric seed traits (L, W, T, Dg, and φ) were measured in the samples belonging to both the National Gene Bank of Tunisia (NGBT) and ICARDA faba bean collection
Faba bean is an important crop for sustainable agriculture in marginal areas and advanced agricultural systems, as it plays an important role in soil fertility and nitrogen fixation, being able to grow in diverse climatic and soil conditions

Summary

Introduction

The wild progenitor of V. faba is unknown, but recent archaeological excavations have allowed, in the. Genes 2020, 11, 236 hypothesize that this species has been domesticated since the Neolithic era, and that the wild progenitor, possibly distributed in small habitats, was entirely domesticated and became extinct [2,3,4,5]. According to Cole [6] and Cubero [7], the spread of faba bean from its center of origin to other countries could have involved five routes. In the Mediterranean, in particular, faba bean mainly spread through two routes: the first across Anatolia to Greece, the Illyric coast (possibly the Danubian regions), and to Italy; the second, beginning at the Nile Delta, moving towards the West, along the North. It is worth mentioning that, in this regard, North Africa and Tunisia in particular constitute a center of primary and secondary diversification of several agricultural and wild species [8]

Methods

Results

Conclusion