Cereal Landraces Research Articles

Trends, challenges and opportunities in the in situ conservation of cereal landraces in Scottish islands

Landraces are traditional crop varieties that often have special adaptations to the farming environment in which they have evolved and are therefore a valuable source of useful traits for plant breeders. In most agriculturally advanced countries, landraces of the main crops have generally been superseded by modern varieties. An exception to this in the United Kingdom is the cultivation on the Scottish archipelagos of Orkney, Shetland and the Outer Hebrides of three cereal landraces: bere, a 6-row barley (Hordeum vulgare), small oat (Avena strigosa) and Hebridean rye (Secale cereale). Our study focused on trends in their cultivation and use over the past 20 years. In the Outer Hebrides, a mixture of all three has continued to be grown on more than 200ha for feed because of its tolerance of nutrient-deficient sandy soils. Future cultivation is threatened, however, by damage from geese and deer, especially to fields used for seed production. In Orkney and Shetland, only bere and small oat are grown, and always as sole crops. The area of bere has increased in Orkney, from about 10ha in 2004 to almost 75ha in 2020 and has been driven by two supply chains producing bere for milling and malting. However, small oat in Orkney, and both small oat and, especially bere, in Shetland have been grown by very few farmers since 2018 and are at serious risk of being lost from cultivation. We discuss these results in the context of measures to support greater on-farm cultivation of these landraces.

Agriculture in Marginal Areas: Reintroduction of Rye and Wheat Varieties for Breadmaking in the Antrona Valley

In marginal lands, cereal landraces continue to be important in agricultural production, whereas hybrids lose their competitive advantage. In this context, selection for adaptation to each environment is particularly important in crops grown under unfavourable conditions, e.g., mountain areas. In this work, from a panel of traditional and modern varieties, mixtures and evolutionary populations, a randomised block experiment was established to select the most productive and suitable wheat and rye varieties specific for the Antrona Valley. The nutritional analysis of each flour was carried out. The results obtained in two years of varietal comparison suggested that rye is more suitable than wheat for growing in this environment: Alpina rye showed the highest yield/m2 and the highest ash content (1.87% ± 0.03%; p < 0.05) compared to other varieties, indicating it as suitable for the baking process. Among wheats, San Pastore showed the highest number of ears/m2 (411 and 350; p < 0.05) compared to others. However, in a context of climate change, the cultivation of Solibam could ensure yield stability, thanks to the high variability within the evolutionary population. Overall, our results demonstrated the possible reintroduction of the cereal supply chain in the Valley and the resumption of the historic rye bread production.

Chemical, Functional, and Technological Features of Grains, Brans, and Semolina from Purple and Red Durum Wheat Landraces.

A main reason of the increasing interest in cereal landraces is their potential to offer more diversified and functional staple food. For instance, landraces are an underexploited resource of pigmented varieties, appreciated for the high accumulation of phytochemicals with known health benefits. This study characterized the chemical, functional, and technological features of the bran, semolina, and grains of two durum wheat (Triticum turgidum L. subsp. durum, Desf.) landraces, named ‘Purple’ and ‘Red’ for their grain color, collected in Ethiopia and grown and sold in southern Italy as a niche product. Specifically, we analyzed the protein content, dry gluten, ash, total polyphenols, anthocyanins, proanthocyanidins, and specific phenolic acids. We also evaluated the antioxidant activity using DPPH- and ABTS-based methods. The two landraces had positive nutritional features, such as a high protein content, a rich and composite range of secondary metabolites (which include specific phenolic acids and anthocyanins), and antioxidant activities in all the fractions analyzed. The germplasm under investigation therefore has a well-justified potential to yield functional products and to diversify durum wheat-based foods.

Genetic and Morpho-Agronomic Characterization of Sicilian Tetraploid Wheat Germplasm.

Cereal landraces are a very valuable resource in contemporary agriculture. A renewed focus for breeding purposes could ameliorate some negative consequences of modern agriculture and conventional breeding, such as the loss of genetic diversity. One strategy combining molecular genotyping and characterization of morpho-agronomic traits related to productivity is proposed to assess a group of tetraploid wheat landraces named Bufala, historically cultivated in the mountain areas of Sicily and characterized by adaptability in terms of cold tolerance, ability to grow in marginal soils, weed competitiveness and resistance to diseases. A total of 55 SSR molecular markers were used to detect patterns of diversity in 30 rivet and durum wheat genotypes. Furthermore, phenotyping was then conducted for 8 morpho-agronomic traits. Discriminant analysis of principal components (DAPC), STRUCTURE and phylogenetical analysis allowed to identify three groups, two of them genetically close and including both Bufala and Bufala-related rivet landraces. To the third group, old and more recent durum wheat varieties, constituting the outgroup, were assigned. Clustering was confirmed by Principal Component Analysis (PCA). Finally, a correlation analysis showed that Bufala genotypes are characterized by lower ear density, major ear length and later earing time compared with the other studied genotypes. The levels of diversity and population structure could be an important contribution to parent selection in tetraploid wheat breeding programs, as well as to germplasm conservation and management.

Importance of Landraces in Cereal Breeding for Stress Tolerance.

The renewed focus on cereal landraces is a response to some negative consequences of modern agriculture and conventional breeding which led to a reduction of genetic diversity. Cereal landraces are still cultivated on marginal lands due to their adaptability to unfavourable conditions, constituting an important source of genetic diversity usable in modern plant breeding to improve the adaptation to abiotic or biotic stresses, yield performance and quality traits in limiting environments. Traditional agricultural production systems have played an important role in the evolution and conservation of wide variability in gene pools within species. Today, on-farm and ex situ conservation in gene bank collections, together with data sharing among researchers and breeders, will greatly benefit cereal improvement. Many efforts are usually made to collect, organize and phenotypically and genotypically analyse cereal landrace collections, which also utilize genomic approaches. Their use in breeding programs based on genomic selection, and the discovery of beneficial untapped QTL/genes/alleles which could be introgressed into modern varieties by MAS, pyramiding or biotechnological tools, increase the potential for their better deployment and exploitation in breeding for a more sustainable agricultural production, particularly enhancing adaptation and productivity in stress-prone environments to cope with current climate changes.

On farm survival of Apulian legume and cereal landraces in relation to land cover/land use changes. A case study

Apulia (southeast of Italy) has always been an agricultural region in the Italian landscape. Nowadays, the countryside is a mix of natural environments and artificial landscapes. From 2014 to 2016, the region has been the object of a project aimed to collect information about geographic position and surface devoted to legume and/or cereal landrace cultivation. The collection missions carried out allowed the acquisition of 352 samples belonging to eight legumes and six cereal species. Chickpeas predominated among legumes, while durum and common wheat landraces prevailed among cereals. The cultivation of these landraces was mainly located in the marginal areas of central and southern Apulia region. The geographical information system technology, used in order to geo-reference the collection sites, allowed investigating the changes in land cover/land use (LCLU) occurred over the last three decades at each collecting site. In addition to the evidences collected at field level, the comparison of old ortho-photos and recent satellite images, available on Copernicus Land Monitoring Service of European Environment Agency, shown that very limited changes of LCLU have occurred. Near the collection sites, the agrarian landscape is remained highly fragmented as it was three decades ago. The cultivation side by side of irregular patches with legumes, cereals, olive trees, and grapevine characterise the agricultural landscape. Based on these evidences it can be infer that the absence of significant changes in LCLU has play a positive role in the safeguard of on farm conservation of Apulian landraces.
 Highlights - Analysis of present distribution of Apulian legume and cereal landraces. - Short description of the landscape of collection sites. - Comparison of present and past diffusion of landrace cultivation. - Changes in land cover/land use that occurred over the last three decades.

Wheat landraces with low mycorrhizing ability at field respond differently to inoculation with artificial or indigenous arbuscular mycorrhizal fungal communities

Conventional farming is not sustainable in a context of climate change and of dramatic reductions in natural resource stocks worldwide. A change of paradigm towards more sustainable farming is necessary, based on the preservation and management of ecosystem services. The soil is a reservoir of organisms beneficial for plant production. Among these are arbuscular mycorrhizal fungi. Nevertheless, the response of plants – especially cereal landraces – to mycorrhization, and the effect of domestication on the response to mycorrhization are controversial. In the present paper we investigated the response of four wheat landraces with a low mycorrhizogenous ability to inoculation with the indigenous arbuscular mycorrhizal fungi community or an artificial community in greenhouse and field conditions. We showed that the community of arbuscular mycorrhizal fungi can have an effect on yield, even in wheat landraces with a low mycorrhizogenous ability. We also highlighted the importance to properly choose the criteria (phenotypic criteria as root and shoot biomasses versus quality criteria as grain quality) used to measure this possible gain.

Searching for the Origins of Bere Barley: a Geometric Morphometric Approach to Cereal Landrace Recognition in Archaeology

Bere is a landrace of barley, adapted to the marginal conditions of northern Scotland, especially those of the Northern and Western Isles. The history of bere on these islands is long and, in an era of diminishing landrace cultivation, bere now represents one of the oldest cereal landraces in Europe still grown commercially. The longevity of bere raises the possibility of using grain characteristics of present-day specimens to identify bere in the archaeological record. Geometric modern morphometric (GMM) analysis of grains from bere and other barley landraces is conducted to determine whether landraces can be differentiated on grain morphology. Results indicate that there are morphological differences between bere and other British and Scandinavian landraces, and between bere from Orkney and the Western Isles, both of which are apparent in genetic analysis. This finding paves the way for the identification of bere archaeologically, helping to establish its status as living heritage and securing its commercial future. More broadly, this work indicates the potential of grain GMM for the recognition of cereal landraces, permitting the ancestry and exchange of landraces to be traced in the archaeological record.

The trans-Eurasian crop exchange in prehistory: Discerning pathways from barley phylogeography

A number of crops that are of global importance today, including wheat (Triticum spp) and barley (Hordeum vulgare), were domesticated in Southwest Asia between 10,000 and 11,000 years ago and subsequently spread through the Old World, into Europe, North Africa and eastwards across Eurasia. Their routes of expansion have been a focus of debate and are increasingly being revealed by widespread dating of archaeobotanical remains from across Eurasia. Of particular interest is work by Zhao (2009) who proposed three routes for the spread of wheat into China: firstly, across the Eurasian Steppe, second by sea from India to the east coast of Eurasia and third, along the Hexi Corridor, which forms part of the Silk Road in western China. Molecular genetic analysis of cereal landraces have also elucidated routes of expansion of cereal cultivation and, in addition, have revealed how crops adapted to changing environments as they moved away from their centres of domestication. Genes involved in flowering time genes have been a particular focus of these studies, including the photoperiod response gene Ppd-H1 in barley, which controls flowering in response to increasing day-lengths in the spring. In this paper we present a phylogeographic analysis of Old World landrace and wild barley, through the analysis of a portion of the Ppd-H1 DNA sequence. We discuss the geographic distribution of different haplotypes of this gene across Eurasia in the light of Zhao (2009)'s three routes and what it potentially reveals about trans-Eurasian pathways of contact between early farming communities.

Recent advances in ancient DNA research and their implications for archaeobotany

The scope and ambition of biomolecular archaeology is undergoing rapid change due to the development of new ‘next generation’ sequencing (NGS) methods for analysis of ancient DNA in archaeological specimens. These methods have not yet been applied extensively to archaeobotanical material but their utility has been demonstrated with desiccated, waterlogged and charred remains. The future use of NGS is likely to open up new areas of investigation that have been difficult or impossible with the traditional approach to aDNA sequencing. Species identification should become more routine with archaeobotanical explants, not just with charred grain but with most if not all species likely to be encountered in an archaeobotanical setting. Distinctions between different subspecies groups such as cereal landraces will also be possible in the near future. Phenotypic characterization, in which aDNA sequencing is used to infer the biological characteristics of an archaeological specimen, will become possible, improving our understanding of traits such as flowering behaviour of cereals, and when combined with studies of preserved RNA and protein will enable complex phenotypes such as environmental tolerance and nutritional quality to be assessed. The sequencing of entire ancient plant genomes is also likely to have significant impact. As with past studies of ancient plant DNA, realization of the new potential provided by NGS will require productive collaboration between archaeologists and geneticists within the archaeobotanical research community.

Genotypic variation in the ability of landraces and commercial cereal varieties to avoid manganese deficiency in soils with limited manganese availability: is there a role for root‐exuded phytases?

The marginal agricultural-systems of the Machair in the Western Isles of Scotland often have limited micronutrient availability because of alkaline soils. Traditional landraces of oats, barley and rye are thought to be better adapted to cope with the limited manganese (Mn) availability of these soils. When commercial cultivars are grown on the Machair, limited Mn-availability reduces crop yield and quality. We hypothesised that traditional cereal landraces selected on the Machair acquire Mn more effectively and that this could be linked to exudation of phytase from roots which would release Mn complexed with inositol phosphates. Growth and Mn-acquisition of five landraces and three commercial cultivars of barley and oats were determined in Machair soil. In addition, root phytase activities were assayed under Mn-starvation and sufficiency in hydroponics. In Machair soil, landraces had greater capacity for acquiring Mn and a greater ability to achieve maximum yield compared to the commercial cultivars. Under Mn-starvation, root phytase exudation was upregulated in all plants, suggesting that this trait might allow cereals to acquire more Mn when Mn-availability is limited. In the landraces, exuded phytase activity related positively to relative Mn-accumulation, whereas in the commercial cultivars this relationship was negative, suggesting that this trait may be secondary to an efficiency trait that has been lost from commercial germplasm by breeding. This research shows that cereal landraces possess traits that could be useful for improving the Mn-acquisition of commercial varieties. Exploiting the genetic diversity of landraces could improve the sustainability of agriculture on marginal calcareous lands globally.

Cereal landraces genetic resources in worldwide GeneBanks. A review

Since the dawn of agriculture, cereal landraces have been the staples for food production worldwide, but their use dramatically declined in the 2nd half of the last century, replaced by modern cultivars. In most parts of the world, landraces are one of the most threatened components of agrobiodiversity, facing the risk of genetic erosion and extinction. Since landraces have a tremendous potential in the development of new cultivars adapted to changing environmental conditions, GeneBanks holding their genetic resources potentially play an important role in supporting sustainable agriculture. This work reviews the current knowledge on cereal landraces maintained in GeneBanks and highlights the strengths and weaknesses of existing information about their taxonomy, origin, structure, threats, sampling methodologies and conservation and GeneBanks’ documentation and management. An overview of major collections of cereal landraces is presented, using the information available in global metadatabase systems. This review on winter cereal landrace conservation focuses on: (1) traditional role of GeneBanks is evolving beyond their original purpose to conserve plant materials for breeding programmes. Today’s GeneBank users are interested in landraces’ history, agro-ecology and traditional knowledge associated with their use, in addition to germplasm traits. (2) GeneBanks therefore need to actively share their germplasm collections’ information using different channels, to promote unlimited and effective use of these materials for the further development of sustainable agriculture. (3) Access to information on the 7.4 million accessions conserved in GeneBanks worldwide, of which cereal accessions account for nearly 45 %, particularly information on cereal landraces (24 % of wheat, 23 % of barley, 14 % of oats and 29 % of rye accessions), is often not easily available to potential users, mainly due to the lack of consistent or compatible documentation systems, their structure and registration. (4) Enhancing the sustainable use of landraces maintained in germplasm collections through the effective application of recent advances in landrace knowledge (origin, structure and traits) and documentation using the internet tools and data providing networks, including the use of molecular and biotechnological tools for the material screening and detection of agronomic traits. (5) Cereal landraces cannot be exclusively conserved as seed samples maintained under ex situ conditions in GeneBanks. The enormous contribution of farmers in maintaining the crop and landraces diversity is recognised. Sharing of benefits and raising awareness of the value of cereal landraces are the most effective ways to promote their conservation and to ensure their continued availability and sustainable use. (6) Evaluation of costs and economic benefits attributed to sustainable use of cereal landraces conserved in the GeneBanks requires comprehensive studies conducted on a case-by-case basis, that take into consideration species/crop resources, conservation conditions and quality and GeneBank location and functions.

Ultrasound influence on coleoptile length at Poaceae seedlings as valuable criteria in prebreeding and breeding processes

The study includes research on the effect of ultrasound on the ability of seed germination and coleoptile development of cereal landraces (fam. Poaceae): oat (Avena sativa L.) brodski, rye (Secale cereale L.) rakotinska, Triticale svetinikolsko and soft wheat (Triticum aestivum L.) govrlevska. The experiment with ultrasound was carried out at frequency of 30-40 kHz on the thermostatic ultrasonic bath. Seeds were sonicated at a constant temperature (25?C) for 15 min. Ultrasound effect is reflected in the length of the coleoptyl and mesocotyl, although in a good deal is genetically predetermined. Coleoptile length was the longest in Triticale (3.3-5.5 cm) and approximately the same lengths are evident in rye (3.0-6.1 cm). Concerning the mesocotyl the longest one (5.525 cm ? 0.697) is recorded at rye, even significantly longer than control of oat and Triticale. Longer coleoptile of sonicated seeds indicates faster seedling development, good water supply and rapid development and emergence of first leaves. Correlation coefficient showed very high (0.821) and high R2 (67,472%) dependence among variables both, in length of coleoptiles (as dependent variable) and mesocotyl (as independent) with low standard error (0.225). With the simple use of ultrasound the germination period could be shorten, water supply more efficient, the sowing periods will be shorten and good yields even under conditions of climate change with increased temperatures could be achieved.

Cereal landraces for sustainable agriculture. A review

Modern agriculture and conventional breeding and the liberal use of high inputs has resulted in the loss of genetic diversity and the stagnation of yields in cereals in less favourable areas. Increasingly landraces are being replaced by modern cultivars which are less resilient to pests, diseases and abiotic stresses and thereby losing a valuable source of germplasm for meeting the future needs of sustainable agriculture in the context of climate change. Where landraces persist there is concern that their potential is not fully realised. Much effort has gone into collecting, organising, studying and analysing landraces recently and we review the current status and potential for their improved deployment and exploitation, and incorporation of their positive qualities into new cultivars or populations for more sustainable agricultural production. In particular their potential as sources of novel disease and abiotic stress resistance genes or combination of genes if deployed appropriately, of phytonutrients accompanied with optimal micronutrient concentrations which can help alleviate aging-related and chronic diseases, and of nutrient use efficiency traits.We discuss the place of landraces in the origin of modern cereal crops and breeding of elite cereal cultivars, the importance of on-farm and ex situ diversity conservation; how modern genotyping approaches can help both conservation and exploitation; the importance of different phenotyping approaches; and whether legal issues associated with landrace marketing and utilisation need addressing. In this review of the current status and prospects for landraces of cereals in the context of sustainable agriculture, the major points are the following: (1) Landraces have very rich and complex ancestry representing variation in response to many diverse stresses and are vast resources for the development of future crops deriving many sustainable traits from their heritage. (2) There are many germplasm collections of landraces of the major cereals worldwide exhibiting much variation in valuable morphological, agronomic and biochemical traits. The germplasm has been characterised to variable degrees and in many different ways including molecular markers which can assist selection. (3) Much of this germplasm is being maintained both in long-term storage and on farm where it continues to evolve, both of which have their merits and problems. There is much concern about loss of variation, identification, description and accessibility of accessions despite international strategies for addressing these issues. (4) Developments in genotyping technologies are making the variation available in landraces ever more accessible. However, high quality, extensive and detailed, relevant and appropriate phenotyping needs to be associated with the genotyping to enable it to be exploited successfully. We also need to understand the complexity of the genetics of these desirable traits in order to develop new germplasm. (5) Nutrient use efficiency is a very important criterion for sustainability. Landrace material offers a potential source for crop improvement although these traits are highly interactive with their environment, particularly developmental stage, soil conditions and other organisms affecting roots and their environment. (6) Landraces are also a potential source of traits for improved nutrition of cereal crops, particularly antioxidants, phenolics in general, carotenoids and tocol in particular. They also have the potential to improve mineral content, particularly iron and zinc, if these traits can be successfully transferred to improved varieties. (7) Landraces have been shown to be valuable sources of resistance to pathogens and there is more to be gained from such sources. There is also potential, largely unrealised, for disease tolerance and resistance or tolerance of pest and various abiotic stresses too including to toxic environments. (8) Single gene traits are generally easily transferred from landrace germplasm to modern cultivars, but most of the desirable traits characteristic of landraces are complex and difficult to express in different genetic backgrounds. Maintaining these characteristics in heterogeneous landraces is also problematic. Breeding, selection and deployment methods appropriate to these objectives should be used rather than those used for high input intensive agriculture plant breeding. (9) Participatory plant breeding and variety selection has proven more successful than the approach used in high input breeding programmes for landrace improvement in stress-prone environments where sustainable approaches are a high priority. Despite being more complex to carry out, it not only delivers improved germplasm, but also aids uptake and communication between farmers, researchers and advisors for the benefit of all. (10) Previous seed trade legislation was designed primarily to protect trade and return royalty income to modern plant breeders with expensive programmes to fund. As the desirability of using landraces becomes more apparent to achieve greater sustainability, legislation changes are being made to facilitate this trade too. However, more changes are needed to promote the exploitation of diversity in landraces and encourage their use.

Yield response of Bere, a Scottish barley landrace, to cultural practices and agricultural inputs

There is very little documented about the response of cereal landraces to modern agricultural practices. Bere is a Scottish barley ( Hordeum vulgare L.) landrace which is grown in Orkney to supply meal for baking. A recent research programme has improved yields and the security of the Bere harvest, making it possible to supply a new market for grain to produce specialist whiskies. At the start of this research, a survey of Orkney farmers who had grown Bere since the 1980s showed that most had planted it at the traditional time in mid-May, used few inputs and considered the main constraints of the crop to be low yield (2.8 to 3.8 t/ha) and susceptibility to lodging. Three years of trials in Orkney between 2003 and 2005 showed very significant increases in grain yield (17-76%) and thousand grain weight from planting Bere earlier, in the second half of April. This also had the advantage of an earlier and more secure harvest. Yields showed smaller, but often significant, increases (5-11%) from applying mineral fertiliser, growth regulator or fungicide, while combinations of growth regulator and fungicide increased yields from 10- 22%. In spite of usually increasing grain yield, growth regulator did not always control lodging. Although the use of inputs often increased the gross margins of growing Bere, a trial in 2005 showed that early planting was a more cost effective single intervention than either the use of fungicide or growth regulator. By increasing grower profits and reducing harvesting risks, these results have made it viable for more farmers to grow Bere in its region of origin, providing growers and end-users with additional income and contributing to the in situ conservation of this landrace.

Approaches and constraints of using existing landrace and extant plant material to understand agricultural spread in prehistory

The potential for the phylogeographical analysis of cereal landraces to determine the initial patterns of agricultural spread through Europe is discussed in relation to two of the first cereals to be domesticated, emmer wheat (Triticum turgidumsubsp.dicoccum) and barley (Hordeum vulgare). Extant landraces available from germplasm collections have a patchy distribution, largely being confined to regions of rugged upland topography, and the phylogeographical patterns observed may be due to ‘overstamping’ by more recent crop movements. Phylogeographical studies of non-viable historical landrace material held in herbarium and old seed collections and found in historical buildings have the potential to fill in the gaps in time and space. We explore the importance of precise geographical provenance and the limitations of this in extant and historical material. Additionally, we consider the effect of various chemicals and the preservation of DNA in the historical material.

Retrospecting genetic variation of Finnish oat (Avena sativa) landraces and observations on revived lines grown prior to 1957

An aged seed sample of a single oat landrace resulted in four plants when germinated. The plants differed from each other morphologically and genetically. They represented four grain types, three lemma colours, three avenin and three residual grain protein patterns and two molar ratios of C18:C16 fatty acids. These old oats grew high under current conditions and some also had yielding potential. Landraces with wide residual to avenin protein ratios would have been good sources in breeding food cereals for coeliac patients. Literature data since the 1700s indicate that Finnish oat landraces included morphological mixtures. Some were intentionally mixed. As also noted for Finnish barley landraces, oat landraces appear to have approached mixtures of genetically unique plants. Several reasons for the variation are presented. Active replacement of landraces (genetic polymorphism) with only a few pure-line cultivars was encouraged by authorities during the Mendelian period. Genetic variation was lost earliest in oats among Finnish cereal landraces. The proportion of oat landraces declined from 100% in 1902 to 34.4% in 1922 and to 0.2% in 1955. Genetic conservation did not occur in time, resulting from lack of foresight by authorities.

Cereal land-races from Austria and their utilization in plant breeding

Land-races are somewhat younger than usually mentioned. Also land-races are not abandoned populations but influenced by a simple continuous, equalizing human selection, as well as by natural evolution. Thus the phenotypical uniformity will be high, while the genetical variability is larger than in commercial bred varieties, but much less than in populations grown in a gene centre. Many effects like resistance, adaptation and continuous annual yield are resulting from the land-race's multiline character, which can be seen as biological model for surviving of agricultural populations. The breeder's effort to isolate certain genes will be troublesome and often less effective because of this multiline symbiosis and genes approaching demand and botanical features of a gone period.