scholarly journals Importance of Landraces in Cereal Breeding for Stress Tolerance

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1267
Author(s):  
Daniela Marone ◽  
Maria A. Russo ◽  
Antonia Mores ◽  
Donatella B. M. Ficco ◽  
Giovanni Laidò ◽  
...  

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.

2003 ◽  
Vol 1 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Toby Hodgkin ◽  
V. Ramanatha Rao ◽  
Angélica Cibrian-Jaramillo ◽  
Samy Gaiji

AbstractPlant genetic resources are conserved so that they can be used to improve crop plant pro- duction and in other ways. However, it is often asserted that use of ex situ conserved germplasm is inadequate and that genetic diversity maintained in genebanks is underutilized. In part, this reflects an incomplete recognition of what constitutes use of plant genetic resources, and of the many different ways in which material from genebanks contributes to improved agricultural production. Based on recent information from surveys of distribution of germplasm from genebanks, and from surveys of users, we suggest that the evidence indicates that there is substantial use of ex situ conserved materials for a wide range of different uses. We suggest that barriers to use of ex situ conserved germplasm may often result from a lack in numbers of users, and from limitations in capacity to effectively utilize the genetic diversity present in genebanks to reduce genetic vulnerability and increase sustainability in modern production systems.


2019 ◽  
Vol 20 (12) ◽  
pp. 2971 ◽  
Author(s):  
Jitendra Kumar ◽  
Arbind K. Choudhary ◽  
Debjyoti Sen Gupta ◽  
Shiv Kumar

Pulses are the main source of protein and minerals in the vegetarian diet. These are primarily cultivated on marginal lands with few inputs in several resource-poor countries of the world, including several in South Asia. Their cultivation in resource-scarce conditions exposes them to various abiotic and biotic stresses, leading to significant yield losses. Furthermore, climate change due to global warming has increased their vulnerability to emerging new insect pests and abiotic stresses that can become even more serious in the coming years. The changing climate scenario has made it more challenging to breed and develop climate-resilient smart pulses. Although pulses are climate smart, as they simultaneously adapt to and mitigate the effects of climate change, their narrow genetic diversity has always been a major constraint to their improvement for adaptability. However, existing genetic diversity still provides opportunities to exploit novel attributes for developing climate-resilient cultivars. The mining and exploitation of adaptive traits imparting tolerance/resistance to climate-smart pulses can be accelerated further by using cutting-edge approaches of biotechnology such as transgenics, genome editing, and epigenetics. This review discusses various classical and molecular approaches and strategies to exploit adaptive traits for breeding climate-smart pulses.


2011 ◽  
Vol 7 (6) ◽  
pp. 1287-1298 ◽  
Author(s):  
Aicha El Oualkadi ◽  
Mohammed Ater ◽  
Zerhoune Messaoudi ◽  
Kaddour El Heit ◽  
Valérie Laucou ◽  
...  
Keyword(s):  
Ex Situ ◽  

2010 ◽  
Vol 25 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Miguel Ayarza ◽  
Elisabeth Huber-Sannwald ◽  
Jeffrey E. Herrick ◽  
James F. Reynolds ◽  
Luis García-Barrios ◽  
...  

AbstractDevelopment of sustainable agricultural production systems in the tropics is challenging in part because the local and external conditions that affect sustainability are constantly in flux. The Quesungual agroforestry system (QSMAS) was developed in response to these changing conditions. The history and potential future of the QSMAS provide an opportunity to consider the factors affecting small-scale agricultural production systems on marginal lands throughout the world. We evaluated the QSMAS in Honduras in the context of the five principles of the Drylands Development Paradigm (DDP) during three periods: pre-QSMAS, QSMAS adoption and the future. The first two periods provided lessons that could be relevant to other regions. The QSMAS system in Honduras must continue to evolve, if long-term benefits are to be realized. We conclude that while the DDP was a useful framework for systematically identifying the critical drivers and processes determining the sustainability of QSMAS in Honduras, it is ultimately no more able to predict the future than the collective knowledge of those who choose to apply it. The DDP, however, can facilitate the integration and application of knowledge.


2021 ◽  
Author(s):  
Samuel Vanden Abeele ◽  
Steven B. Janssens ◽  
Justin Asimonyio Anio ◽  
Yves Bawin ◽  
Jonas Depecker ◽  
...  

Premise: Many cultivated coffee varieties descend from Coffea canephora, commonly known as Robusta coffee. The Congo Basin has a century long history of Robusta coffee cultivation and breeding, and is hypothesized to be the region of origin of many of the cultivated Robusta varieties. Since little is known about the genetic composition of C. canephora in this region, we assessed the genetic diversity of wild and cultivated C. canephora shrubs in the Democratic Republic of the Congo. Methods: Using 18 microsatellite markers, we studied the genetic composition of wild and backyard-grown C. canephora shrubs in the Tshopo and Ituri provinces, and from the INERA Yangambi Coffee Collection. We assessed genetic clustering patterns, genetic diversity, and genetic differentiation between populations. Key results: Genetic differentiation was relatively strong between wild and cultivated C. canephora shrubs, and both gene pools harbored multiple unique alleles. Strong genetic differentiation was also observed between wild populations. The level of genetic diversity in wild populations was similar to that of the INERA Yangambi Coffee Collection, but local wild genotypes were mostly missing from that collection. Shrubs grown in the backyards were genetically similar to the breeding material from INERA Yangambi. Conclusions: Most C. canephora that is grown in local backyards originated from INERA breeding programs, while a few shrubs were obtained directly from surrounding forests. The INERA Yangambi Coffee Collection could benefit from an enrichment with local wild genotypes, to increase the genetic resources available for breeding purposes, as well as to support ex situ conservation.


2017 ◽  
Vol 142 (5) ◽  
pp. 319-329 ◽  
Author(s):  
Yu Zong ◽  
Ping Sun ◽  
Xiaoyan Yue ◽  
Qingfeng Niu ◽  
Yuanwen Teng

Pyrus betulaefolia is one of the most popular pear (Pyrus) rootstocks in China and other east Asian countries because of its good adaptability to versatile environments. However, the number of wild P. betulaefolia populations is decreasing because of habitat destruction and fragmentation. An urgent evaluation of P. betulaefolia genetic diversity and population structure is necessary to develop a conservation strategy for this important wild species. Thirteen simple sequence repeat loci were detected to infer the genetic composition of 18 P. betulaefolia populations in northern China. The average number of different alleles for each locus was 7.1. The number of effective alleles among loci ranged from 1.77 to 5.94. The overall mean values of expected and observed heterozygosity were 0.702 and 0.687, respectively. The Taihang Mountains, which run from northeast to southwest, acted as natural boundary in shaping the genetic diversity of P. betulaefolia in northern China. The distinct pattern, which was also observed in the distribution of chloroplast DNA (cpDNA) variation, appeared to be obscured by pollen-mediated gene flow in the distribution of nuclear microsatellite variation. Large populations with high allelic richness (e.g., populations BT, ZN, and QS) are considered suitable for in situ conservation because of the potential for adaptation to future environmental change. The smaller populations had mixed gene pools (e.g., populations GQ and XF) and should therefore also be considered for ex situ conservation. Preserving genetic diversity in seeds was proposed when field collections are fully characterized.


1970 ◽  
Vol 7 ◽  
pp. 1-10
Author(s):  
BK Joshi ◽  
A Mudwari ◽  
MR Bhatta

Genetic diversity must be maintained and utilized for sustainable agriculture development. Theamount of genetic diversity in the country depends on the number and diversity of the originalancestors involved in the creation of a germplasm pool, wild relatives and existing landraces.The objective of this research was to study the diversity of wheat gene pool present in theNepalese bread wheat cultivars and landraces that could help for developing conservation andutilization strategy effectively. We examined the pedigrees of 35 Nepalese wheat cultivars andsurveyed the literature for distribution of landraces and wild relatives of wheat. Cultivatedlandraces of spring and winter type, wild landraces and diploid species of wheat are found inNepal. There are 35 improved wheat cultivars, 540 landraces and 10 wild relatives of wheat.Crosses between winter and spring wheat gene pools are far more common and offer a newsource of diversity. Mexico, India and Nepal are the origin countries for 35 cultivars. In Nepalfour cultivars were bred and developed using foreign landraces and maximum number ofcultivars was developed in Mexico. Lerma 52, first improved cereal variety to be released in thehistory of cereal breeding in Nepal was released in 1960. A total of 89 ancestors originated in 22different countries were used to develop these cultivars. Highest number of ancestors was fromIndia. Ancestors of both aestivum and durum species having winter, spring and intermediategrowth habit indicated the collection of wide gene pool. Most of the ancestors were aestivum(76.40%) and spring growth habit (57.31%). Modern varieties are replacing the landraces andimproved old varieties resulted in the genetic erosion. Therefore, in situ, on farm and ex situconservations are necessary for maintaining these genetic variations. Unutilization of locallandraces in breeding program may be the major factor that causes to accelerate the geneticerosion. Gene pool from these landraces along with international gene pool could make towardssuccess in developing high yielding cultivars with wide adaptability. In this study, cultivars andlandraces surveyed represent a wide range of variation for different areas of origin andadaptation.Key words: Ancestor; landrace; origin; wheat gene poolDOI: 10.3126/narj.v7i0.1859Nepal Agriculture Research Journal Vol.7 2006 pp.1-10


2020 ◽  
Author(s):  
Miguel Angel Muñiz-Castro ◽  
Gabriela Lopez-Barrera ◽  
Maried Ochoa-Zavala ◽  
Patricia Castro-Felix ◽  
Jose Antonio Vazquez-Garcia ◽  
...  

Abstract Background: Genetic diversity is needed to preserve the capability of a species to survive to environmental changes. Due to the presence of small isolated populations, relict species such as Magnolia are at an elevated extinction risk. In recent years, many new species of Magnolia have been described in Mexico, each one classified by its category of risk. To achieve conservation, knowledge of their basic level of biological diversity is essential to design adequate conservation plans and avoid the negative consequences of genetic loss. Here, we implemented nuclear microsatellite markers to assess 13 populations of three new species of Magnolia that were all previously considered to be Magnolia pacifica. We aimed to evaluate the genetic agreement with the distinction of these three different morphological species (e.g., their species integrity) and to determine their levels of genetic diversity and their geographic distribution to propose conservation strategies. Results: We found high levels of genetic diversity compared to other Magnolia species with no sign of inbreeding. We found a small effective population size and a prevalence of bottlenecks in some populations. The patterns of genetic subdivision did not support the current morphological distinction of three different species. Instead, we suggest that the genetic structure pattern is the result of historical connectivity and the continuous natural fragmentation of the forest. Thus, an isolation by distance pattern may have had an important role in shaping allele frequencies, producing local genetic differences. Conclusions: We argue that a major threat underlies the actual trends of habitat loss, which can directly impact the loss of genetic diversity in the current adult individuals and consequently, increase the risk of extinction in further generations. For conservation purposes, we suggest combining in situ and ex situ conservation of populations with the maintenance of connectivity among the local populations.


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