Traditional Breeding System Research Articles

Assisted reproductive technologies (ARTs) in Mithun (Bos frontalis): What progress has been made so far? An overview.

Mithun, a unique bovine species, endemic to parts of North East India and plays an important role in the socioeconomic, cultural and religious fabrics of the local tribal population. To date, Mithuns are reared in a traditional free-range system by communities and increased deforestation, agricultural commercialization, disease outbreaks and indiscriminate slaughtering of elite Mithun for table purposes have significantly decreased its habitat and the elite Mithun population. Greater genetic gain is achieved with the implementation and effective use of assisted reproductive technologies (ARTs); however, presently it is limited to organized Mithun farms. At a slow pace, Mithun farmers are adopting semi-intensive rearing systems and interest in the use of ARTs is gradually escalating in Mithun husbandry. This article reviews the current status of ARTs such as semen collection and cryopreservation, estrus synchronization and timed artificial insemination (TAI), multiple ovulation and embryo transfer and in vitro embryo production and future perspectives in Mithun. Mithun semen collection and cryopreservation have been standardized, and estrus synchronization and TAI are suitable technologies that can be easily implemented under field conditions in near future. The establishment of an open nucleus-breeding system under community participatory mode along with the introduction of the ARTs is an alternative to the traditional breeding system for rapid genetic improvement of Mithun. Finally, the review considers the potential benefits of ARTs in Mithun and future research should include the use of these ARTs which will provide additional opportunities for improved breeding regimens in Mithun.

황기의 유전체 기반 SSR 마커 개발

Background: Although Astragalus membranaceus is a major medicinal herb used for food and medicinal purposes, genome-based research for its exploration is insufficient. The introduction of the genetic breeding system for medicinal crops, based on genomic analysis, will have a great impact not only on the establishment of the origin but also on understanding the existing traditional breeding system.<BR>Methods and Results: A. membranaceus from five accessions of Poongsung, Asung, Jecheon, Sancheong, and Jilin from China were used, which are cultivated in the test field. The produced nucleotide sequences were assembled de novo to obtain 450,449 contigs, and the repeat sequences were extracted using the selection criteria, two to six nucleotide sequences repeated five time or more. Finally, we obtained 147,766 simple sequence repeat (SSR) marker candidates. Using the CLC genomics workbench program, 949 SSR markers showing mutations for Astragalus in the 5 accessions were selected. From the designed primer sets, 99 were randomly selected and applied to the genomic DNA which was extracted from five cultivars and pooled. Ten primer sets showing more than two bands were finally selected as SSR markers, and were used for the genetic relationship analysis in 81 strains of A. membranaceus.<BR>Conclusions: The data of this study can be used as a marker when registering A. membranaceus varieties through pure line selection and line breeding in the future. It is thought that it can greatly contribute to securing intellectual property rights for domestic Astragalus breeding varieties.

Genetic diversity and phylogenetic relationships within local pigs in southern Benin.

The current context of climate change requires the conservation of local zoogenetic resources already very well adapted to the traditional breeding system, rough feeding, and heat and cold stress. This study assessed genetic diversity in local pigs in southern Benin, as a prerequisite for their sustainable use and sustainable management in Benin. A total of 69 individuals including 54 local pigs, 7 Large-White, and 8 hybrids (local pigs × Bush-pig) were genotyped by using 17 microsatellite markers. On the average, 8.94 alleles were detected per locus. Average expected and observed heterozygosities were respectively 0.51 and 0.46. Polymorphic information content was 0.61, and genetic diversity was 0.53. A phylogenetic tree gathered local pigs into three genetic clusters. Genetic structural analyses revealed introgression of Large-White's genes into the local pig's genome. Three groups were identified: hybrids (subpopulation 1), a mixture of Large-White and local pigs (subpopulation 2), and only local pigs (subpopulation 3). Symmetrical allelic distances were higher between subpopulations 1 and 2 (0.787) and then 1 and 3 (0.713). The same trend was detected for genetic distances between pairs of subpopulations. Genetic differentiation between subpopulations 2 and 3 was very weak as a consequence of high gene flow (10.82). Molecular variance analysis showed that 77% of genetic diversity within populations was related to variability between the individuals. These results showed that local pigs in southern Benin are threatened by genetic erosion and suggest prompt actions to implement sustainable conservation strategies.

From National Biosecurity Measures to Territorial ASF Preparedness: The Case of Free-Range Pig Farming in Corsica, France.

In response to African swine fever (ASF) outbreaks in wild boars in Belgium in 2018, the French authorities issued national biosecurity measures for all pig farms, regardless of their geographical and socio-technical scale. Considering the Corsican pig farmers' demonstrations against these measures (for geographical, cultural, and economic reasons), this article questions the suitability of standardized top-down national measures that potentially endanger traditional breeding systems, which are increasingly marginalized in relation to the dominant industrial model. From an action-research approach, the article analyzes how local stakeholders go beyond usual classical biosecurity issues to propose a territorialized preparedness. Mediating between Corsican farmers and the government representatives, a technical committee made up of actors from various regional research and development bodies drew up a socially acceptable preparedness proposal. Viewing the health risk from a local standpoint, the committee provided arguments for maintaining the extensive grazing that is non-negotiable for the farmers, while getting the farmers to agree to change other practices (reproduction control) as a measure against health hazards already present. Analysis of the preparedness process and the mediation process shows that a territorialized bottom-up approach to the governance of health risks can make biosecurity measures more acceptable to farmers. It also points to the legitimacy of a set of alternatives to top-down measures that standardize farming systems and may lead to the disappearance of small farmers and their traditional systems.

Sustainability of Four Dairy Farming Scenarios in an Alpine Environment: The Case Study of Toma di Lanzo Cheese.

The dairy sector accounts for a large share of all European agricultural production, at the same time however, it is one of the most ascribed sector contributors to the environmental impact of agriculture, particularly for greenhouse gas emissions. Simultaneously, it is a strategic sector for the economy but generates increasing debate in the community regarding the social aspects mainly related to the use of resources and the food-feed competition of livestock involving the reduction of human-edible crops. In this general framework, this study aims to compare four different dairy farming scenarios characterized by different use of environmental resources in the Alpine area, considering as a case study the production of the Toma di Lanzo cheese (a traditional cheese produced in the mountainous regions of Piedmont—Northwest Italy). The study envisaged the integrated use of three methodologies: Life Cycle Assessment, Life Cycle Costing and the assessment of human-edible feed conversion efficiency to jointly analyze environmental, economic and social aspects. The main results of this research highlighted how the utilization of local breeds, which maximize the efficiency in the use of territory resources, such as grasslands in a mountain environment, allowed dairy production to reduce emissions, when compared to the high-input traditional breeding systems. Although the mountain livestock systems have several critical issues mainly linked to social factors such as low generational turnover, work schedules, modest life quality of families, it is however possible to earn more income than in lowland scenarios. At the same time, this production system allows the Toma di Lanzo cheese-making heritage to be preserved. This mountain pasture cheese, to which superior organoleptic and nutritional characteristics are attributable, when compared to cheeses from the valley floor, incorporates traditional values, a link to the territory and the transmission of knowledge. With reference to food-feed competition in livestock involving the reduction of the use of human-edible crops and feedstuffs in animal diets, we found that grazing and grass-based feeding systems were one of the most sustainable ways to produce milk.

Effects of Pre-milking Resting on Some Lactation Characteristics of Damascus (Shami) and Kilis Goats

This study was carried out with the aim of determining the effects of pre-milking resting on some milk yield characteristics in Damascus (Shami) and Kilis goats. The milk yield characteristics of the two breeds were also compared in the study. The goats in both genotypes were divided into two groups as Control (10 heads) and Treatment (10 heads). All goats grazed at the same pasture during day-time in accordance with traditional breeding system of the region. And, they were offered 1 kg/head/day concentrate containing 16 % crude protein and 2600 kcal metabolizable energy in dry matter when they returned to the pen. The control group goats were milked by hand while they feeding the concentrate. The treatment group goats were rested an hour after concentrate feeding and then they milked by hand. At the end of the study the effect of the application and the breeds on the milk yield and milk composition were not significant (p&amp;gt;0.05), except for the lactose content (p&amp;lt;0.01). Moreover, the effect of the lactation months on the content of all fatty acids in the milk were also detected statistically important (p&amp;lt;0.05).

Influence du type génétique sur la composition corporelle et la qualité de la viande des ovins élevés dans les systèmes d’élevage traditionnels

Objetivou-se avaliar o perfil fermentativo, as perdas e a composição química da silagem de Brachiaria brizantha cv. Piatã com diferentes aditivos. O delineamento experimental foi inteiramente casualizado, com quatro repetições por tratamento e cinco tratamentos com diferentes aditivos, como segue: T1- controle sem aditivos; T2 - inoculante microbiano SiloMax Centurium (Matsuda); T3 - inoculante ênzimo microbiano Sil All C4 (Alltech do Brasil); T4 - fubá de milho (100 g kg-1 na matéria natural) e T5 - glicerina bruta (100 g kg-1 na matéria natural), totalizando 20 silos experimentais. A adição de fubá de milho elevou os teores de matéria seca (MS) e carboidratos não-fibrosos (CNF) com diminuição na fibra em detergente neutro (FDN). A maior perda de MS total (124,7 g kg-1) foi observado para a silagem sem aditivos, enquanto que a adição de fubá de milho reduziu as perdas de MS total (32,2 g kg-1). Os menores valores de pH foram observados nas silagens com fubá de milho e acidez titulável e os mais elevados nas silagens com glicerina bruta, bem como uma maior produção de ácido láctico. Recomenda-se a inclusão de fubá de milho em 100 g kg-1 de matéria natural, uma vez que fornece um melhor perfil fermentativo e composição química, além de reduzir as perdas de MS. Além disso, a inclusão de glicerina em 100 g kg-1 de matéria fresca mostrou-se como um aditivo com potencial de utilização.

Pathology and genetic findings in a rare case of Mycobacterium caprae infection in a sow

Bovine tuberculosis, a reemerging zoonosis in diverse ecological scenarios, has been reported in the autochthonous Nebrodi black pig breed population used for meat production in Italy. During a routine abattoir inspection in 2013, 24 of 299 carcasses (8%) of Nebrodi black pigs presented tuberculosis-like lesions at pathologic examination. Mycobacterium bovis was isolated from 23 animals and M. caprae from a 3-year-old sow. The sow showed severe diffuse lesions involving the visceral organs, right coxofemoral joint, and mammary glands. Isolation of M. caprae from mammary glands is uncommon, with only one other case involving a sow reported so far; however, Mycobacteria infection of the mammary glands may be transmitted from lactating sows to piglets, contributing to the spread and maintenance of bovine tuberculosis in swine. Genotyping analysis showed M. caprae spoligotype SB0866 and profile 4,1,5,4,4,11,4,2,4,3,8,7 MIRU-VNTR (mycobacterial interspersed repetitive units-variable number of tandem repeats). The worldwide prevalence of this spoligotype is very low. The finding of severe, diffuse tuberculous lesions strongly suggests that Nebrodi black pigs are susceptible for Mycobacterium spp. and that they might act as a distributor for these microorganisms. Since natural ecosystems with multiple contacts among different livestock species and wild animals are very common in Mediterranean regions, current surveillance and eradication plans for bovine tuberculosis will need to be extended to other potential reservoir species in regions where extensive and traditional breeding systems are operated.

The performance of Bali Cattle in transmigration area, south Kalimantan: a financial analysis

This research was conducted in the sub-district of Takisung, district of Tanah Laut, South Kalimantan Province in 2012. This paper was aimed to know the farming performance of the Bali Cattle rearing system in the transmigration area reared by the transmigrant groups of Harapan Makmur, Sumber Rejeki, Tunas Muda and Darmarwulan, that were selected using purposive sampling as the primary data. The agroecosystem that supported the area consisted of palm oil, rubber and agricultural land. Secondary data was obtained from province agriculture officer and district livestock officer. The results of the study showed that the benefits of calf crop beef cattle rearing system (traditional breeding system) in the group of Harapan Makmur was around IDR 5,295,200/year with B/C ratio of 1.28, whereas the value of the benefits of the group of Tunas Muda was around IDR 4,105,800/year with B/C ratio of 1.22. The value of the benefit of feedlot cattle rearing system in the groups of Sumber Rejeki was around IDR 2,110,000/3 months with B/C ratio of 1.07 and the value of the benefits of the group of Damarwulan was around IDR 5,760,000/3 months with B/C ratio of 1.09. Land resource and source of manpower strongly supported the development of cattle farming with the ownership of 2-4 head/family, both the cows and the bull are very economical, effective and efficient in those business so that would benefit to the farmers group.

Growth Allometry among the Rabbit of Amoron i Mania

The rabbits have a special feature for adaptation to the different types of food and climate. In addition, the composition of food and the mode of farming have a consequence to the mode of growth and body composition of the rabbit. In Madagascar, the research focused on rabbits is very rare. In this case, we found an absence of documents of reference concerning the growth of existing rabbits in the region of Amoron i Mania. A thorough research for the biological characteristics of these existing breeds is desired in order to improve this field. Then the objective of this study is to understand the type of rabbit growth in this region of study within a mathematical equation. During the conduct of this study, 1052 rabbits from the 100 family farms are measured. For the population of the rabbit measured in this region, the global allometric coefficient is 2.32 which is significantly equal to the theoretical allometry (b = 3), equivalent to an isometric growth. Therefore, the increase in weight is evolving in parallel with the increase in the length. The result by race has always shown the same type of growth except the blue of Vienna variety which presented a negative allometric growth. The distribution of samples by sex and by district has also figured this type of isometric growth. This type of growth belongs to rabbits which reach slowly its weight. This state of slow growth could be a result of the practice of an extensive and traditional breeding system which generally stands on a poor diet to the rabbit. Then this study allows establishing a tool to estimate the weight of the rabbit from the total length. The equation LW = 0,3558LT2,3224 was chosen as a model of allometric equation applicable to livestock.

Bioinformatics tool for handling molecular data in wheat breeding

The research institute in Martonvasar is one of the largest agricultural research institutes in Hungary and in Central Europe. For many years now, the accumulated data on the extensive wheat breeding stocks has been handled and analysed using programs developed in the institute. The information system that has been elaborated and constantly improved can be used for keeping records of breeding stock, for planning field and laboratory experiments, for site-plant performance evaluation, for automated data collection, for the rapid evaluation of the results and for effective management of the pedigree, seed exchange and the institute’s cereal gene bank. The demand for the storage of molecular data and their use in breeding has increased parallel with the development of new, PCR-based markers. For this reason, informatics tools (data structure and software) suited to the design of marker-assisted selection experiments and the interpretation of the results have been developed as part of the existing Martonvasar wheat breeding information system. The aim was to link molecular data to the phenotypic information already available in the database and to make the results available to wheat breeders and geneticists. The interpretation of molecular data related to specific genotypes is of assistance in clarifying the genetic background of economically important phenotypic traits, in identifying markers linked to the useful genes or agronomic traits to be found in the genomics database, and in the selection of satisfactory parental partners for breeding. Marker assisted selection coupled with traditional breeding activities enables the breeder to make plant selections based on the presence of target genes. Conventional wheat breeding with the integrated molecular component allows breeders to more accurately and efficiently select defined sets of genes in segregating generations. The molecular data are stored in a relational database, the central element of which is the [DNASource] entity. This is used to collect and store information on gene sources arising during breeding. It is therefore linked both to the phenotypic data stored in the traditional breeding system (measurements, observations, laboratory data) and to the component parts of the new, molecular data structure ([PrimerBank], [Marker], [Allele] and [Gene]).

Efeito da duração do tratamento com progestágeno e da maturidade sexual na taxa de prenhez em novilhas de corte: avaliação econômica e biológica

Os objetivos neste experimento foram avaliar o efeito do tempo de exposição a um progestágeno (P4) na taxa de prenhez de novilhas púberes e pré-púberes inseminadas em tempo-fixo (IATF) e estudar o retorno econômico dos protocolos utilizados, por meio da comparação desses protocolos ao sistema tradicional de acasalamento natural aos 26 meses de idade. Foram utilizadas 114 novilhas da raça Bradford com 16 meses de idade, classificadas em quatro grupos de acordo com o tratamento e a maturidade sexual: GPPLP - pré-puberes, longo tratamento com P4 (n=21); e GPPCP - pré-puberes, curto tratamento com (n=19); GPLP - púberes, longo tratamento com P4 (n=34); e GPCP - púberes, curto tratamento com P4 (n=40). As novilhas do GPPLP e GPLP receberam no dia -8 um pessário intravaginal impregnado com acetato de medroxiprogesterona. No dia 0, o pessário foi removido e outro foi inserido, juntamente com uma injeção de 2,5 mg de benzoato de estradiol (BE). No dia 8, o pessário foi retirado e as novilhas receberam 0,5 mg de BE e 250 µg de cloprostenol sódico. A inseminação artificial em tempo fixo (IATF) foi realizada 54 horas depois. As novilhas do GPPCP e GPCP receberam o mesmo tratamento de sincronização dos grupos GPPLP e GPLP, com exceção do AMP do dia -8 ao dia 0. A taxa de prenhez foi maior nas novilhas púberes (60,3%) que nas pré-puberes (35,0%). No entanto, não foi detectado efeito do tempo de tratamento na taxa de prenhez nas novilhas púberes e pré-puberes. A resposta econômica na utilização de protocolos com P4 foi maior em novilhas aos 16 meses que no sistema de acasalamento aos 26 meses. A exposição prolongada a um P4 não foi eficiente para aumentar a taxa de prenhez de novilhas submetidas a IATF.

A note on the reproductive success of primiparous blue fox vixens in social groups

Our aim was to compare traditional breeding system, i.e. artificial insemination with singly-housing, to alternative breeding systems in farmed blue fox ( Alopex lagopus or Vulpes lagopus) vixens. At the age of 7 weeks (i.e. at weaning), 48 randomly selected female blue fox cubs were divided into four experimental groups: (1) artificially inseminated singly-housed vixens in cages (AI-SC), (2) artificially inseminated pair-housed vixens in double-cages (AI-PC), (3) naturally bred pair-housed vixens with a male in triple-cages (NB-PC), and (4) naturally bred pair-housed vixens with a male in outdoor enclosures (NB-PE). The cubs were counted on days 1, 2, 3, 7, 14 and 49 postpartum and the reproductive performance per breeding (RPB) and per mated vixens (RPM) with its subcomponents were formed from these data. RPB was zero in both NB groups. In AI-PC and AI-SC, RPB was 1.3 ± 2.5 and 4.1 ± 4.7 cubs, respectively. RPB and the percentage of vixens that weaned cubs were lower in NB-PC and NB-PE than in AI-PC. In AI groups, both RPB and RPM at weaning tended to be better in singly-housed than in pair-housed blue fox vixens. No statistically significant differences were found between AI groups in the percentage of vixens without oestrus, barren vixens, vixens that lost all cubs or weaned at least one cub. Only in one pair (AI-PC) both vixens displayed communal breeding and weaned cubs. The present results show that vixens in traditional breeding system had better RPM than in any of the studied pair-housing systems. The current blue fox population has been effectively selected for cage-breeding and artificial reproduction, and therefore blue foxes generally reproduce well with artificial insemination after careful detection of oestrus in traditional breeding conditions.

Estudo da influência de diferentes alimentos sobre características quantitativas e qualitativas da gordura em porcos de raça alentejana

In this study, we tested three foodstuffs, complementary to the traditional breeding system (“montanheira”): a commercial foodstuff, a cereal (triticale) and a mixture of triticale, oats and soybean meal. Each foodstuff was given to the Alentejano pigs in order to supply the following digestible energy contents daily: 4250 kcal between 30 and 40 kg of live weight; increasing thereafter until reaching 6800 kcal at 60-70 kg of live weight; and then progressively decreasing until 4800 kcal, at 90-100 kg of live weight. After analysing the results, we found positive correlations between the percentages of palmitic acid (C16:0) and estearic acid (C18:0), both in the L. dorsi muscle and in the subcutaneous adipose tissue. We also found negative correlations between the percentages of oleic (C18:1) and linoleic (C18:2) acids in both tissues. We found significant differences between feedstuffs in what concerned total amount of fat, as well as relative values of C18:1 and C18:2 in subcutaneous fat. Triticale was the feedstuff that led to a larger amount of fat in the carcasses (16,65 ± 1,06 kg). It also led to a greater amount of intramuscular lipids in the L. dorsi muscle (5,54%), even though this difference was statistically non significant. On the other hand, this was the feedstuff that led to a higher C18:1 value (48,76%) and to a lower C18:2 value (5,52%). These characteristics, combined with the ease of production of this feedstuff at the farm, can make triticale an interesting option for organic pig farmers, as long as the amounts fed are restricted, in order not to diminish the commercial worth of carcasses because of excess of fat.

Out of season sheep milk production in Sardinia

Sheep breeding in Sardinia is based on two lambing seasons: in autumn for adult and in late winter for primiparous ewes. The milk production is concentrated within the winter-spring period, determining a break in the cheese factories’ activities from the middle summer to the middle autumn. In order to have a continuous milk production over all the year an out-of-season sheep farming model was tested in Sardinian irrigated lowland. 52 Sarda dairy ewes, 20% of which primiparous, were mated in October with a lambing season in March. The experimental flock grazed rotationally a forage model based on 66% of irrigated surface. Flock fertility and prolificacy resulted 100% and 1.58, respectively. During the suckling period the average lamb growth rate was 255 + 0.08 g head d-1. The average milk yield resulted 279 l head-1 in 180 milking days (290 and 258 l head-1 for adult and primiparous ewes, respectively). Average milk fat and protein contents were 5.8% and 4.7% respectively. The study suggested that it is possible to integrate an out of season milk production with the traditional breeding system in Sardinian irrigated lowlands.

Survey on housing, management and welfare of dairy cattle in tie-stalls in western Italian Alps

In the Alps, the traditional breeding system for dairy cattle is based on the alternation between a free-ranging period on mountain ranges during the summer, and an indoor period in tie-stalls in the winter. Several welfare issues may arise in tie-stall housing systems. We describe the situation in 47 farms in three villages in western Italy, trying to identify possible relationships among structural and management characteristics, animal health and behaviour traits. A long duration of the grazing period, associated with frequent manure removal during the housing period, are probably key factors for limiting the occurrence of lameness. Teat trauma is more common in narrower stalls. Getting-up behaviour is unnatural in most of the visited farms. Some lack in the farmers’ knowledge of animal behaviour was noted. Some structural and management characteristics are strictly related to geographical constraints. However, circumstances permitting, some expedients may be achieved for improving welfare levels.

Genetic transformation technology: Status and problems

Transfer of genes from heterologous species provides the means of selectively introducing new traits into crop plants and expanding the gene pool beyond what has been available to traditional breeding systems. With the recent advances in genetic engineering of plants, it is now feasible to introduce into crop plants, genes that have previously been inaccessible to the conventional plant breeder, or which did not exist in the crop of interest. This holds a tremendous potential for the genetic enhancement of important food crops. However, the availability of efficient transformation methods to introduce foreign DNA can be a substantial barrier to the application of recombinant DNA methods in some crop plants. Despite significant advances over the past decades, development of efficient transformation methods can take many years of painstaking research. The major components for the development of transgenic plants include the development of reliable tissue culture regeneration systems, preparation of gene constructs and efficient transformation techniques for the introduction of genes into the crop plants, recovery and multiplication of transgenic plants, molecular and genetic characterization of transgenic plants for stable and efficient gene expression, transfer of genes to elite cultivars by conventional breeding methods if required, and the evaluation of transgenic plants for their effectiveness in alleviating the biotic and abiotic stresses without being an environmental biohazard. Amongst these, protocols for the introduction of genes, including the efficient regeneration of shoots in tissue cultures, and transformation methods can be major bottlenecks to the application of genetic transformation technology. Some of the key constraints in transformation procedures and possible solutions for safe development and deployment of transgenic plants for crop improvement are discussed.

Das globale Huhn

The loss of agrobiodiversity is an upcoming field on international policy agendas. The case study “global chicken” reveals the causes of the loss of agrogenetic resources of chicken. This loss is caused by agricultural research linked with economic interests and property right systems as well as the enforcement of a fordist production model in the agricultural sector with immense distributional effects especially on agrogenetic resources. The hybrid chicken breeding industry destroys genetic resources by “outcompeting” traditional breeding systems.

Genetic transformation of cassava (Manihot esculenta Crantz).

Genetic engineering can be used to complement traditional breeding methods in crop plant improvement. Transfer of genes from heterologous species provides the means of selectively introducing new traits into crop plants and expanding the gene pool beyond what has been available to traditional breeding systems. The prerequisites for genetic engineering are efficient transformation and tissue culture systems that allow selection and regeneration of transgenic plants. Cassava, an integral plant for food security in developing countries, has until now been recalcitrant to transformation approaches. We report here a method for regenerating stably transformed cassava plants after cocultivation with Agrobacterium tumefaciens, which opens cassava for future improvement via biotechnology.