Introduction

Ensuring future global food security is one of the biggest challenges facing humans today. One in nine people worldwide already suffers from poor access to food resources (FAO, IFAD and WFP, 2015), and with predicted human population growth, pressure on food resources is likely to increase dramatically (Godfray et al., 2010; UN DESA, 2015). New high-yielding varieties of crops that can withstand adverse climatic conditions and new pests and diseases are urgently needed (McCouch et al., 2013). All cultivated crops derive from historic human domestication of wild genotypes, which have been gradually selected to produce commercial varieties (Engels & Thormann, 2020). Crop wild relatives are the wild original sources of these modern cultivars and remain the primary resource of genetic diversity for breeding new, climate-change tolerant, and higher-yielding cultivars (Maxted & Kell, 2009; Vincent et al., 2019). As such, it is vital to ensure wild relatives are identified, protected and propagated to help secure the future of the species we depend on.

Globally, fruit trees are of enormous economic importance. In many places (Ercişli, Güleryüz, Orhan, Ertürk, & Karlıdağ, 2009; Otieno, 2017), the wild relatives of fruit trees (WRFT) remain essential sources of food and medicines (Symphorien et al., 2016) but also provide feed for domestic animals and food additives. They also play a crucial role in maintaining ecological diversity (Musayev & Huseynova, 2016). Notably, some of these wild relatives are known to possess traits that could greatly benefit contemporary agriculture through the breeding of new, improved cultivars. For example, wild genotypes of species in the genus Prunus are characterized by adaptation to extreme climatic conditions (Uğur & Gündeşli, 2020). Moreover, wild fruit tree genotypes are an essential source of resilient rootstock, as grafting is one of the key methods for making new fruit varieties available to growers (Zhebentyayeva et al., 2019). Several wild edible fruits are used by rural and tribal populations and significantly contribute to their livelihood. The use of non-cultivated foods, of which wild fruits form a part, as a dietary supplement or as a coping mechanism in times of food shortage, provides an important safety net for the rural poor, especially in low-income countries (Ercişli & Sagbas, 2017).

The term underutilized and neglected species refers to a category of wild and cultivated plant species characterized by a low level of investment in research and development, and a recognized but untapped livelihood potential (Eyzaguirre, Padulosi, & Hodgkin, 1998). Widespread genetic erosion of these species has been recorded worldwide: for example, in Nepal, more than half of the traditional landraces have become absent from the farmer's fields (Paudel, Joshi, & Ghimire, 2016). Generally, despite several initiatives in recent years aimed at the conservation of such genetic resources, these wild relatives are still at risk of erosion or extinction (Pilling et al., 2020). They have been almost entirely neglected in ex situ genebanks (Castañeda-Álvarez et al., 2016), although some efforts to change this have begun (Dempewolf et al., 2013). In addition, current in situ reserves often do not meet the required management standards to maintain the wild relatives and their genetic diversity for long-term use (Iriondo et al., 2012; Weibull & Phillips, 2020).

Syria lies within a region of substantial topographic and climatic diversity in the Fertile Crescent, which is the centre of origin and domestication of many globally important crops. Syria is rich in agrobiodiversity (food, forage crops and fruit trees) like wheat, barley, lentils, chickpeas, vetch, olives, almonds, pear, plums, medic, clover, as well as other ornamental, medicinal and aromatic plants. Such plants are the main stocks and heritage for farming in Syria and are widely used elsewhere in the world. According to the Fourth National Report on Biodiversity in Syria (MSEA, 2009), the reduction in plant genetic resources was caused by urbanization, climate change, decreasing rainfall and increasing temperatures in dry seasons, which the region has experienced in the last seven years. An increasing incidence of wildfires also poses a particular threat.

During the conflict period from 2012 to 2019, Syria lost 20.4% of its tree cover (Gaafar, 2021), much of it in Idlib and Lattakia governorates. The depletion of wild tree populations has been associated with several factors related to the conflict, including intense reliance on trees for heating and shelter, frequent fires in wild forests, charcoal production, illegal logging, agricultural expansion, and the weakness of state institutions in protecting natural resources and in managing environmental development. The losses of wild tree species include the cherry Prunus mahaleb, oak trees, wild pines and hundreds of other plant (tree and crop) species are also threatened.

Unfortunately, there is no data available about the current situation of the WRFT, the only available data were published by FAO (1996), which clearly mentioned the deterioration of plant genetic resources in Syria started before the crisis. It can be assumed that the deterioration of WRFT has increased following the ongoing crisis in Syria resulting from the absence of any control for the protection of these genotypes against the deterioration. Moreover, there was clear evidence of plant genetic resources decline in northwest (NW) Syria based on the finding of previous research about crop landraces in the same locations in NW Syria (AlDarvish et al., 2022) The primary causes were the spread of cultivation to new areas, the need to grow economic crops, particularly cereals, forages and food legumes, and accidental forest fires (AlDarvish et al., 2022; FAO, 1996). Hence the WRFT were already facing extinction before the Syrian crisis began. Since then, the absence of research authorities responsible for the conservation and propagation of genetic resources has severely exacerbated the problem. Currently, no conservation activity is occurring as the conflict is preventing any access to the field by Syrian botanists, in particular in mountain areas where the threat from mines and bombs is severe (Valderrabano, Gil, Heywood, & Montmollin, 2018).

As a first step towards addressing the lack of activity on these vital global resources, this study aimed to: i) collect information about the current status and critical threats to ten species of WRFT in NW Syria, ii) characterize and map the locations of WRFT exposed to deterioration, and iii) collect seed from multiple genotypes of each species to be used for the establishment of an in situ and ex situ WRFT collection.

Materials and methods

Results

Focus group discussions conducted with community representatives and experts in the agricultural sector in the targeted subdistricts showed that several WRFT locations had been subject to neglect after the Syrian crisis and had experienced significant deterioration (Figure 1).

Data from the 50 interviews showed that WRFT were found in the following four types of locations within the study area: forests, verges along agricultural roads, rocky and neglected parts of farms, and working farms. The percentage of responses among the 50 participants for the distribution of WRFT in study locations is illustrated in Figure 2.

The interviews revealed that the following ten WRFT species are experiencing erosion: Prunus mahaleb, Prunus orientalis, Vitis vinifera, Rhus coriaria, Olea europaea, Crataegus azarolus, Ficus carica, Pistacia atlantica, Prunus spinosa, and Pyrus syriaca.

A range of reasons was reported for WRFT deterioration (Figure 3). The primary causes were overgrazing, frequent droughts and climate change. The predominant conflict-related factors reported were neglect by local authorities, lack of awareness of the importance and value of WRFT and deforestation resulting from the collection of wood for fuel and conversion to arable lands. Several respondents mentioned the lack of interest by the younger generation in making use of local wild fruit landraces, overuse (massive unmanaged fruit gathering), desertification and expansion of building into forest locations as contributing factors. Floods were not considered a threat by any of the respondents. Based on the assessment result with the interviewees, the reasons for erosions of WRFT are equal within all areas of the study.

With respect to the impact of the ongoing conflict in NW Syria on WRFT, all participants stated that the Syrian armed conflict had intensified the deterioration due to the lack of government control leading to overgrazing and excessive cutting of trees in these locations.

When questioned about conservation actions that were considered to be the most important for the protection of WRFT against the current deterioration, participants responses showed the following answers: 36% suggested exchanging seeds of WRFT with other farmers, 26% supported the establishment of local collections for multiplication of these species, 22% considered public awareness campaigns and 14% favoured seed collection and conservation of these species in local genebanks. Only 2% considered awareness campaigns to be the most important action for the protection and preservation of these species.

Regarding the availability of seeds or cuttings of the WRFT species, 56% of the participants stated that seeds or cuttings of these species were not available, whereas 44% stated that they have access to seeds and cuttings. This response suggests that some WRFT are currently at high risk of decline and may even suffer extinction over time.

Discussion

Future food security for humankind is likely to rely heavily on the sustainable availability of a wide range of plant genetic resources for food, agriculture and nutrition, amongst other needs. WRFT are highly valued genetic resources for food production and to support the livelihoods of rural populations, especially in low-income countries. WRFT in Syria are threatened by extinction due to conflict, which has led to increased direct pressure on the tree populations themselves, and to an absence of research authorities working in the field of conservation and propagation of genetic resources. Consequently, there is a high risk that this vital resource may be lost to future research, and its fruits to future generations.

Our results parallel those of previous studies, which have identified that plant genetic resources in Syria are particularly exposed to deterioration arising from the ongoing conflict (AlDarvish et al., 2022; Gaafar, 2021). However, similar threats to wild plant genetic diversity have also been reported worldwide (Castañeda-Álvarez et al., 2016; Iriondo et al., 2012; Paudel et al., 2016).

Prior to this study, the most recent available information on the current status of WRFT dates from 11 years ago (FAO, 1996) before the start of the conflict. At that time in the study area, the key locations for WRFT were rich in wild genotypes because they were protected by government authorities such as the Ministry of Agriculture and the Directorates of Environmental Protection. As reported by our interviewees, the absence of state protection has resulted in increased deterioration of WRFT populations in these locations, as exploitation such as grazing or cutting of fuelwood for heating is now uncontrolled (Gaafar, 2021). This neglect and lack of protection for WRFT by state institutions has and continues to exacerbate ongoing pressure from climate change and is resulting in severe genetic erosion of these species. As government bodies have not been present in the study area for over a decade, the condition of WRFT has continued to deteriorate, as reported by Valderrabano et al. (2018). Moreover, all interviewees stated that the weakness of current state institutions, which demonstrate little interest in wild fruit trees, has led to increased genetic erosion and deterioration of these genotypes in NW Syria.

WRFT are highly valued for use directly as food resources and as commodities that contribute to livelihoods, especially in rural populations in low-income countries. They are also an essential source of genetic diversity for breeding new, higher-yielding, climate change-tolerant varieties. Despite their high value for food and agriculture (Engels & Thormann, 2020; Ercişli & Sagbas, 2017; Maxted & Kell, 2009; Musayev & Huseynova, 2016; Symphorien et al., 2016; Uğur & Gündeşli, 2020; Vincent et al., 2019; Zhebentyayeva et al., 2019), WRFT have been almost entirely neglected in both ex situ and in situ conservation programmes. As they are likely to be locally adapted and genetically distinctive, WRFT can provide vital novel variation for domesticated fruit species to help meet the challenge of increasingly stressful environments and climatic changes. For example, they have been used by plant breeders to develop more efficient nutrient uptake and utilization, and to integrate genes for adaptation to stressful environments such as water stress, salinity and high temperatures (Ayenan et al., 2019; Mishra, Chowrasia, & Mondal, 2022). As for WRFT,Spiegel-Roy (1986) stated that wild relatives of fruit trees are one of the essential resources for fruit tree breeding, especially for disease tolerance, rootstocks and genetic engineering.

To secure the future of these vital resources, conservation protection efforts are urgently needed for the degraded areas they occupy. The priority species we have identified need to be included in plantation programmes to secure the genetic diversity that will be needed for the improvement of commercially cultivated crops. Countries of the Near East and the Mediterranean basin have perhaps the longest tradition in fruit cultivation for historical, environmental and evolutionary reasons (Barone & Caruso, 1998; Bissessur et al., 2019; Khoury et al., 2017; Migicovsky & Myles, 2017; Wolf et al., 2000).

This study represents the first step in highlighting the extremely threatened status of these genotypes. Our initiative to obtain accurately mapped locations for these genetic resources can underpin future research efforts towards ex situ and in situ conservation programmes. Furthermore, the seed we have collected will form the start of a local genebank collection for future studies of genetic variation and propagation, which can help to ensure resilient and sustainable agricultural development for future generations in Syria and worldwide.

Acknowledgments

This research was supported by Cara (the Council for At-Risk Academics), United Kingdom. The Syrian research team wishes to extend their thanks to Joan Cottrell and Stephen Cavers for their valuable assistance in developing the manuscript.

Supplemental data

Interview questionnaire

Author contributions

Munzer Aldarvish coordinated the research and contributed to the research design and manuscript; Anas Al Kaddour, Akram Bourgol, and Yasser Ramazan contributed to the research design and manuscript and undertook the data analyses, Yousef Hallak contributed to the research design and carried out the field data collection; Stephen Cavers and Joan Cottrell provided academic guidance and support throughout the research process and contributed to the manuscript.

Conflict of interest statement

The authors of this manuscript have no conflicts of interest to declare. All co-authors have seen and agree with the contents of the manuscript, and there is no financial interest to report. We certify that the submission is original work and is not under review at any other publication.