Monographs on underutilized and neglected crops

An initiative is presented which is intended to promote the conservation and use of underutilized and neglected crops. The aim of this project is to identify key information sources and to systematically compile, analyze and disseminate information on a selected set of neglected crop species/gene pools with a view to facilitate the development of a well-targeted global plan of action to improve their conservation and use. The resulting information base will support continued research on these neglected crops. So far, 24 monographs have been published.     

Nature of taro (Colocasia esculenta (L.) Schott) genetic diversity prevalent in a Pacific Ocean island, Vanua Lava, Vanuatu

Taro (Colocasia esculenta (L.) Schott), cultivated in Vêtuboso, a village of northern Vanuatu, Melanesia, was surveyed to: (1) assess the extent of morphological and molecular variation being maintained by growers at the village level and, (2) compare this diversity with the diversity found in the crops in Vanuatu. Ethnobotanical data were combined with AFLP analysis to elucidate possible sources of variation. Folk assessment of variation is based on: (a) morphological characteristics (11 characters), (b) names and (c) classification according to habitat, uses, origin and agronomic adaptation. This 3-fold approach allowed growers to differentiate 96 morphotypes, all of which are given distinct vernacular names. AFLP fingerprints successfully differentiated all these 96 morphotypes which do not present a significant intra-clonal variation. But genetic results showed no clear groupings according to geographic origin or habitat of morphotypes and stated that the diversity found within the village was comparable with the overall diversity found in Vanuatu. Local nomenclature and stories associated with each cultivar suggested three sources of diversity: introductions (38%), somatic mutations (15%) and sexual recombinations (48%). AFLP results confirm folk beliefs about origin at least for three pairs of mutants. The 11 so-called wild forms analysed by AFLP were suggested to be feral, escapes from domestication. A dynamic in situ conservation strategy (DISC), favouring a broadening of the national genetic base, was discussed for taro.     

全球重要农业文化遗产地的农业生物多样性 特征及其保护与利用

2002年联合国粮食及农业组织提出了"全球重要农业文化遗产(GIAHS)"的概念和动态保护理念,旨在建立全球重要农业文化遗产及其有关的景观、生物多样性、知识和文化保护体系,并在世界范围内得到认可与保护,使之成为可持续管理的基础。自此以后,特别是在全球环境基金的支持下,GIAHS的概念和保护理念已经得到越来越多的国家和国际组织的认可,并在项目实施过程中,通过项目试点地的积极探索,不仅使遗产地农业生物多样性和文化多样性得到有效保护,而且促进了遗产地经济社会的可持续发展。本文根据中国已被列入GIAHS的11个项目点及其保护工作,从遗传多样性、物种多样性、生态系统多样性、景观多样性以及文化多样性5个方面分析了农业文化遗产地农业生物多样性的特征,阐述了农业文化遗产地农业生物多样性利用的生态学思想以及原则,最后从建立监测和评估体系、强化农业生物多样性保护与可持续管理的研究、建立农业生物多样性保护的激励机制、建立农业文化遗产地自我维持和持续发展机制等4个方面,提出了农业文化遗产地农业生物多样性保护与利用的若干建议。     

Changes in the diversity and geographic distribution of cultivated millet (Pennisetum glaucum (L.) R. Br.) and sorghum (Sorghum bicolor (L.) Moench) varieties in Niger between 1976 and 2003

Changes in the diversity of landraces in centres of diversity of cultivated plants need to be assessed in order to monitor and conserve agrobioversity—a key-element of sustainable agriculture. This notably applies in tropical areas where factors such as increased populations, climate change and shifts in cropping systems are hypothesized to cause varietal erosion. To assess varietal erosion of staple crops in a country subjected to various anthropogenic and natural environmental changes, we carried out a study based on a comparison of the diversity of pearl millet and sorghum varieties collected in 79 villages spanning the entire cereal-growing zone of Niger over a 26 year period (1976–2003). For these two crops, the number, name and type of varieties according to important traits for farmers were considered at different spatial scales (country, region, village) at the two collection dates. The results confirmed the high diversity of millet and sorghum varieties in Niger. No erosion of varietal diversity was noted on a national scale during the period covered. Some changes were observed but were limited to the geographical distribution of certain varieties. This highlights that farmers’ management can preserve the diversity of millet and sorghum varieties in Niger despite recurrent and severe drought periods and major social changes. It also indicates that rainfed cereal cropping systems in Niger should remain to be based on millet and sorghum, while reinforcing farmers’ seed systems.     

Functional identity has a stronger effect than diversity on mycorrhizal symbiosis and productivity of field grown organic tomato

Beneficial soil biota, and in particular, arbuscular mycorrhizal fungi (AMF) are increasingly being recognized as key elements of organic and low-input agriculture where agrobiodiversity is central to enhanced crop production. However, the role of AMF in diversified organic systems, especially in field crops, is still poorly understood. A 3-year field experiment was carried out in Central Italy to investigate whether organic cropping systems that promote species and genetic diversity are more prone to mycorrhizal symbiosis increasing tomato growth, production and yield quality. Three tomato cultivars with varying genetic diversity were grown following four cover treatments: Indian mustard (Brassica juncea L. Czern.), hairy vetch (Vicia villosa Roth), a commercial mixture of seven cover crop species (Mix 7) and no-till fallow. Plants were either inoculated or not in nursery, with the two AMF isolates Funneliformis mosseae (IMA1) and Rhizoglomus intraradices (IMA6) used alone or mixed in a 1:1 volume ratio. On average, Mix 7 produced higher shoot dry matter (5.0 t ha⁻¹) than V. villosa (3.5 t ha⁻¹) or B. juncea (2.5 t ha⁻¹). Pre-transplant inoculation increased tomato root colonization at flowering and harvest compared to the non inoculated plants (31.8 vs 23.6%) and cv. Rio Grande was on average the best colonized. The mean fresh weight of marketable fruits was 18.4, 28.0 and 28.6 t ha⁻¹ for cvs. Rio Grande, Roma and Perfect Peel, respectively. Cover crops inconsistently affected tomato marketable fruit production in year 1, while in years 2 and 3, Vicia villosa and Mix 7 showed the best effect respectively. In year 3, among the pre-inoculated plants those treated with isolate IMA6 showed a higher production of marketable fruit number m⁻² (56.7) than those inoculated either with IMA1 (51.5) or the mixed inocula (52.1). Most fruit quality parameters were affected by tomato genotype. This study shows that while increased agrobiodiversity is important to increase agroecosystem resilience, AMF, crop and cover crop functional identity may be more important than diversity per se to promote mycorrhizal symbiosis and productivity of field grown organic tomato.     

Ecology and morphological traits of an ancient <Emphasis Type="Italic">Musa acuminata</Emphasis> cultivar from a mountain oasis of Oman

Recent reports have shown a surprising diversity of agricultural crops in Omani oases which was attributed to the country’s traditional role at the crossroads of cultures and trade between the Middle East and Asia. Recent surveys have indicated a relatively small diversity of banana (Musa spp.) germplasm which was thought to reflect the prevailing hyperarid conditions of Oman where this drought-sensitive species can only be cultivated in well-watered oases in the North or in Dhofar, the monsoon-dominated south eastern tip of the Sultanate. Surveys near Umq Bi’r, a half-abandoned oasis in the hardly accessible spring area of Wadi Tiwi, famous with Arabic sailors for its abundant fresh water resources, led to the discovery of a so far undescribed triploid Musa acuminata cultivar surviving in a limestone rock niche. Its morphological traits are different from any of the currently grown banana cultivars. Since acuminata bananas are quite sensitive to drought spells, characteristic for the Arabian Peninsula, the occurrence of this specimen provides further evidence for Oman’s role as a refuge of relict crops imported from a more humid region such as coastal East Africa and nearby islands, or Indonesia.     

Oman at the cross-roads of inter-regional exchange of cultivated plants

During the past years the Sultanate of Oman which is located at the south-eastern tip of the Arabian peninsula has been studied for its cultivated plant genetic resources. Data from this study, that commenced in 2002 and information from the literature have been combined to document the millenia-old cultivation history of many agri- and horticultural crop plants in this country at the cross-roads of inter-regional exchange. The resulting checklist comprises 194 species from 133 genera and 53 families and 11 geoelements of 136 selected species. Notable inputs came from South and Southeast Asia with 21.3%, from the Near East and East Mediterranean with 20.6%, and from Central and South America with 15.4%. Most elements are allochthonous while real autochthonous elements such as Boswellia sacra Flueck. and Prunus arabica (Oliv.) Meikle are rare. A remarkable infraspecific variation in several crop species and evidence of introgession were found indicating an evolutionary power of Oman that is similar to that of South Italy.     

The Importance of Biodiversity in Agroecosystems

SUMMARY

This article identifies the important functions and benefits of biodiversity in agriculture, for sustainable crop production and food security. After clarifying impacts from the decline of biodiversity in agriculture, the article summarizes principles, practices and policies for biodiversity conservation and enhancement in farming systems and in landscapes. Some of the strategies identified build upon valuable local experiences and knowledge in traditional farming practices, while others take advantage of recent scientific findings in agroecology and ecosystem health. The analysis suggests the value of adopting an agroeco-systems approach, beyond a focus on genetic resource conservation alone-to implement other biodiversity-enhancing methods in farms, such as integrated ecological pest and soil management. Attention is also given to the challenges by conflicting agricultural policies that contribute to the decline of biodiversity in farming systems, and potential of reforming such policies. The practices and approaches reviewed in this analysis show effective ways to link biodiversity conservation and sustainable agriculture.     

Agrobiodiversity of Hulled Wheats in Asturias (North of Spain)

Emmer and spelt are two species of hulled wheats that once were widely cultivated in Spain. Today on much reduced extension, these crops are still grown in Asturias (Northern of Spain). A recent expedition to this region was made with the purpose of collecting representative samples of the genetic variability, and compares these materials with those collected previously and conserved in Germplasm Banks. During the field trips, 35 populations were collected with a high diversity, although it was lower than that described in the past. The results of this comparison indicated that great part of this diversity is in risk of further losses in the remain native hulled wheat, mainly due to a progressive introduction of foreigner spelt with better harvest characteristics.     

Analysis of diversity in the fruit tree genetic resources from a Mediterranean island

A large number of genotypes of different fruit tree species have been described in Sardinia, where the plant species have evolved by adaptation to the Mediterranean environment. In this work results are summarized of a long-term survey carried out in the island by the authors since the early 1980s. Ten fruit tree species have been surveyed and collections of the traditional varieties were established. Some are major staple crops such as olive and grape, others such as almond, cherry, plum, fig, apple and pear are nowadays less cultivated, and still others have been more recently introduced like apricot and cactus pear. Data on the level of inter and intra-species diversity are given, as illustrated by representative morphological traits. The results of isozymes and RAPD-PCR analysis on the species Ficus carica genotypes are included, to assess genetic relationship among accessions. Observations on composition, as well as on state of conservation of selected traditional varieties are reported, and the main causes of genetic erosion are listed.