Nuevos genes y herramientas para el manejo de malas hierbas en habas

Weeds are one of the greatest threats to faba bean (Vicia faba L.) production and herbicide application is known to be the most efficient weed control method. However, the susceptibility of the current cultivars to post emergence herbicide applications impose a limitation for weed control in faba bean. Therefore, the deployment of postemergence herbicide tolerance is desirable in faba bean. To address this, a set of 130 faba bean accessions were screened for their response to the recommended dosages of two herbicides, metribuzin at 250 g a.i. ha−1 and imazethapyr at 75 g a.i. ha−1 at Marchouch and Terbol stations during four seasons between 2014 and 2018. The herbicide damage score along with other phenological and yield related traits were recorded and analyzed to evaluate the effects of post emergence herbicide application on the tested accessions and to select the herbicide tolerant ones. Tolerance to metribuzin and imazethapyr in eight faba bean accessions was confirmed as no significant reduction in grain yield resulted from the herbicide application. Moreover, in the aim to identify superior and broad adapted herbicide tolerant faba bean genotypes and to identify the most discriminating environments for herbicide screening, 37 accessions with different levels of tolerance to the recommended dosages of metribuzin and imazethapyr were selected to further evaluate the performance and stability of their plant height and grain yield across different environments (location x season x herbicide treatment). Data collected at Marchouch and Terbol during four seasons between 2014 and 2019 were used and the evaluation was based on the following stability parameters: cultivar superiority, static stability, Wricke’s eco-valence and Finlay and Wilkinson’s regression model. Differences observed in the genotypes ranking suggest that the evaluation of performance and stability of herbicide tolerant faba beans should be based on a combination of stability parameters. Genotype * environment biplot analysis indicated that the environments representing the metribuzin treatment at Marchouch 2014–2015 and the non-treated treatment at Terbol 2018–2019 are the ideal environments for evaluating faba bean genotypes. Biplots showed also that the metribuzin and imazethapyr tolerant accession IG12983 is the ideal genotype as he showed good and stable plant height and grain yield performance across the environments. Finally, to identify molecular markers associated with key genes imparting tolerance to herbicides the same set of accessions phenotyped before was genotyped using genotyping by sequencing (GBS). The GBS yield 10,794 high quality single nucleotide polymorphisms (SNPs). 10 and 14 SNPs highly associated with phenological and yield related traits under herbicide treatments were identified after conducting Single-trait and Multi-trait Genome Wide Association Studies (GWAS) respectively. Genomic sequences containing herbicide tolerance associated SNPs were aligned against the NCBI database using BLASTX tool and default parameters to annotate candidate genes underlying the causal variants. SNPs from acidic endochitinase, LRR receptor-like serine/threonine-protein kinase RCH1, probable serine/threonine-protein kinase NAK, malate dehydrogenase, photosystem I core protein PsaA and MYB-related protein P-like were significantly associated with herbicide tolerance traits. The identified SNPs will facilitate and fasten the efficient and effective development of herbicide tolerant cultivars and can be used for introgressing herbicide tolerance into desired agronomic background.Las malas hierbas se consideran como mayor amenaza para la producción de las habas (Vicia faba L.) ya que no se dispone de métodos efectivos de control adecuados particularmente en el estado de postemergencia. En un intento de mejorar la tolerancia a los herbicidas de postemergencia más comunes, se evaluó durante cuatro años la respuesta de una colección de 130 accesiones de habas a las dosis recomendadas de metribuzin (250 g i.a. ha−1) e imazetapir (75 g i.a. ha−1) en condiciones de campo en las estaciones experimentales de Marchouch (Marruecos) y Terbol (Líbano). Estos trabajos han permitido confirmar la tolerancia de ocho accesiones a metribuzin y a imazetapir. Asimismo, se ha estudiado la estabilidad de componentes del rendimiento de 37 accesiones de habas con diferentes niveles de tolerancia a las dosis recomendadas de ambos herbicidas en diferentes ambientes (localidad x año x tratamiento con herbicida). Los resultados mostraron que la estabilidad de la respuesta en habas tolerantes a herbicidas se basa en una combinación de efectos. Los análisis de interacción Genotipo*Ambiente mostraron el tratamiento con metribuzin en Marchouch 2014-2015 y el control sin herbicida en Terbol 2018-2019 son los ideales para evaluar los genotipos de habas con tolerancia a herbicidas. La accesión IG12983 tolerante a ambos herbicidas mostró una altura de planta y rendimiento de grano altos y estables en todos los ambientes. Finalmente, la colección de habas fue genotipada por secuenciación (Genotyping by Sequencing “GBS”), resultando en la identificación de 10.794 polimorfismos de un solo nucleótido (SNP) de alta calidad. El análisis de asociación (Genome Wide Association “GWAS”) permitió la identificación de 10 y 14 SNP altamente asociados con tolerancia a los herbicidas, según se analizara por un solo o por múltiples caracteres, respectivamente. Las secuencias genómicas que contenían SNP asociados con la tolerancia a los herbicidas se alinearon con la base de datos del NCBI utilizando y la herramienta BLASTX y parámetros predeterminados para anotar los genes candidatos subyacentes a las variantes causales. Los SNP de la endoquitinasa ácida, la serina/treonina-proteína quinasa RCH1 similar al receptor LRR, la probable serina/treonina-proteína quinasa NAK, la malato deshidrogenasa, la proteína PsaA del núcleo del fotosistema I y la “MYB”- relacionada con proteína “P-like” se asociaron significativamente con los caracteres de a tolerancia a herbicidas. Estos SNP identificados permitirán acelerar el desarrollo eficiente y eficaz de cultivares tolerantes a herbicidas

Genetic Dissection of Heat Stress Tolerance in Faba Bean (Vicia faba L.) Using GWAS

Heat waves are expected to become more frequent and intense, which will impact faba bean cultivation globally. Conventional breeding methods are effective but take considerable time to achieve breeding goals, and, therefore, the identification of molecular markers associated with key genes controlling heat tolerance can facilitate and accelerate efficient variety development. We phenotyped 134 accessions in six open field experiments during summer seasons at Terbol, Lebanon, at Hudeiba, Sudan, and at Central Ferry, WA, USA from 2015 to 2018. These accessions were genotyped using genotyping by sequencing (GBS), and 10,794 high quality single nucleotide polymorphisms (SNPs) were discovered. These accessions were clustered in one diverse large group, although several discrete groups may exist surrounding it. Fifteen lines belonging to different botanical groups were identified as tolerant to heat. SNPs associated with heat tolerance using single-trait (ST) and multi-trait (MT) genome-wide association studies (GWASs) showed 9 and 11 significant associations, respectively. Through the annotation of the discovered significant SNPs, we found that SNPs from transcription factor helix–loop–helix bHLH143-like S-adenosylmethionine carrier, putative pentatricopeptide repeat-containing protein At5g08310, protein NLP8-like, and photosystem II reaction center PSB28 proteins are associated with heat tolerance

Evaluation of performance and stability of new sources for tolerance to post-emergence herbicides in lentil (Lens culinaris ssp. culinaris Medik.)

Yield losses in lentil (Lens culinaris ssp. culinaris Medik.) caused by weeds are estimated at 20–80%. In the absence of effective broad-spectrum herbicides, the menace of weed has emerged as a serious yield constraint in lentil. Aims. Identification of tolerance to two broad-spectrum post emergence herbicides, imazethapyr and metribuzin. Methods. 221 lentil accessions were screened at the experimentalresearch station of the International Centerfor Agricultural Research in the Dry Areas, Terbol (Lebanon) over four crop seasons (2014/15–2018/19). During the 2014/15 season, a preliminary screening experiment was conducted with 221 lentil accessions in an alpha lattice design with two replications, where accessions were treated at the pre-flowering stage at 150% of the recommended dose of imazethapyr (112.5 g active ingredient/ha) or metribuzin (315 g active ingredient/ha). Based on the preliminary results, 38 accessions were selected for further evaluation. In subsequent testing, the selected accessions were screened at 100% and 150% of the recommended doses of imazethapyr or metribuzin. Key results. Herbicide treatments delayed the flowering time and maturation of tested lentil accessions. The plant height of selected tolerant accessions was reduced by 15% and 8% in the plots treated by imazethapyr and metribuzin, respectively. Reduction index (RIsy) was an effective tool to select for herbicide tolerance. Stability analysis indicated that two accessions (IG4400 and IG5722) performed under high rainfall environments while two other accessions (IG323 and IG4605) were adapted to low rainfall environments. Conclusions. Four accessions (IG323, IG5722, IG4400, IG4605) were identified as independently tolerant to metribuzin and imazethapyr. Implications. The identified herbicide-tolerant accessions can be used to develop herbicide-tolerant cultivars

Experimental on-farm trials data of faba bean and wheat intercropping field validation in Lebanon and Morocco

This data paper describes the content of four datasets col- lected by the International Center for Agricultural Research in the Dry Areas (ICARDA) as a partner in the project “Designing InnoVative plant teams for Ecosystem Resilience and agricultural Sustainability (DIVERSify)”with the objec- tive of assessing the feasibility of faba bean-wheat mix- ture in Mediterranean environments under diverse rainfed conditions. Data was collected during the trials conducted in Kfardan-Lebanon during 2017/2018 where 40 faba bean varieties were evaluated as sole and as mixture with 2 wheat cultivars ‘Margherita’ and ‘Miki’ and during 2018/2019 where 40 faba bean varieties and one durum wheat cultivar ‘Margherita’ were evaluated under low rainfall environments. Trials were also conducted in Tal Amara-Lebanon during 2019/2020 where 20 faba bean lines and one durum wheat cultivar ‘Margherita’ were evaluated under high rainfall en- vironments and in Marchouch-Morocco during 2019/2020 where 7 faba bean lines with 3 cultivars and one durum wheat cultivar ‘Margherita’ were evaluated under extremely low rainfall environments. A detailed list of the different bi- ological traits collected for wheat and faba bean is found in the specification table in this article. The Kfardan 2018/ 2019, Tal Amara and Marchouch data is related to the conference paper “Performance of faba bean-wheat mixture under di- verse Mediterranean environments”

Genomic regions associated with herbicide tolerance in a worldwide faba bean (Vicia faba L.) collection

Weeds represent one of the major constraints for faba bean crop. The identification of molecular markers associated with key genes imparting tolerance to herbicides can facilitate and fasten the efficient and effective development of herbicide tolerant cultivars. We phenotyped 140 faba bean genotypes in three open field experiments at two locations in Lebanon and Morocco against three herbicide treatments (T1 metribuzin 250 g ai/ha; T2 imazethapyr 75 g ai/ha; T3 untreated) and one in greenhouse where T1 and T3 were applied. The same set was genotyped using genotyping by sequencing (GBS) which yield 10,794 high quality single nucleotide polymorphisms (SNPs). ADMIXTURE software was used to infer the population structure which revealed two ancestral subpopulations. To identify SNPs associated with phenological and yield related traits under herbicide treatments, Single-trait (ST) and Multi-trait (MT) Genome Wide Association Studies (GWAS) were fitted using GEMMA software, showing 10 and 14 highly significant associations, respectively. Genomic sequences containing herbicide tolerance associated SNPs were aligned against the NCBI database using BLASTX tool using default parameters to annotate candidate genes underlying the causal variants. SNPs from acidic endochitinase, LRR receptor-like serine/threonine-protein kinase RCH1, probable serine/threonine-protein kinase NAK, malate dehydrogenase, photosystem I core protein PsaA and MYB-related protein P-like were significantly associated with herbicide tolerance traits

Status of Faba Bean (Vicia faba L.) in the Mediterranean and East African Countries

Faba bean (Vicia faba L.) was first domesticated in the Fertile Crescent of the Near East. It ranks fourth among the cool season food legumes and is now grown in more than 66 countries. Faba bean is a versatile crop; besides being an important source of protein for food and feed, it offers many services for the ecosystem. The Mediterranean and East African countries account for nearly 32% of the global faba bean production. However, the interest in growing faba bean in these countries does not seem to meet their demand even though it is a crop of great economic and social importance there and it is well adapted to Mediterranean-like environments and to the Highlands of subtropical environments. Numerous factors affect the production of faba bean in the Mediterranean and East African countries including the limited financial support that is posing a challenge to the crop improvement for the major production and adoption constraints such as the biotic and abiotic stresses and the antinutritional components. While major achievements have been made toward the development of faba bean varieties having desired traits, there is still a lot of work to be done. The high level of genetic diversity in faba bean accessions and the available molecular markers will considerably help tighten the gap between the production and the demand in the Mediterranean and East African region.Peer reviewe

Adaptability and Stability of Faba Bean (Vicia faba L.) Accessions under Diverse Environments and Herbicide Treatments

The adaptability and stability of 37 faba bean (Vicia faba L.) accessions with different levels of tolerance to metribuzin or imazethapyr was assessed across 12 season–location–herbicide experiments. Significant Genotype x environment (GE) interaction was found for the days to flowering (DFLR), plant height (PLHT) and grain yield (GY). Performance and stability of the accessions regarding PLHT and GY were assessed using four different stability parameters: cultivar superiority, static stability, Wricke’s eco-valence and Finlay and Wilkinson’s regression model. The stability parameters ranked these genotypes differently suggesting that PLHT and GY stability should be assessed not only on a single or a few stability parameters but on a combination of them. GGE biplot analysis indicated that the environments representing metribuzin treatment at Marchouch 2014–2015 and the non-treated treatment at Terbol 2018–2019 are the ideal environments for evaluating faba bean genotypes. GGE biplots showed herbicide tolerant accession IG12983 with simultaneous average PLHT, GY and stability across the environments. The performance of other tolerant accessions, namely IG13945, IG13906, IG106453, FB2648, and FB1216 was less stable but superior under specific mega environments. Therefore, utilizing these accessions in faba bean breeding programs would help broaden the adaptability to diverse locations–season–herbicide treatments

Identification of tolerance to metribuzin and imazethapyr herbicides in faba bean

Weeds cause serious constraint to faba bean (Vicia faba L.) productivity. Broad weed control is hampered by the availability of postemergence herbicides to control them, as the current faba bean cultivars are highly susceptible to them. Therefore, the deployment of postemergence herbicide tolerance is desirable in faba bean. To address this, 130 accessions were screened for their response in mature plants under field conditions to the recommended dosage of two herbicides, metribuzin at 250 g a.i. ha−1 and imazethapyr at 75 g a.i. ha−1 at Marchouch and Terbol stations. The recorded herbicide damage score (HDS) varied from 1 (no visual damage) to 5 (full damage with death of more than 50% of plants) at both locations. Low but highly significant (p < .01) and positive correlation (+0.26) was obtained between the recorded HDS at both locations. Both herbicides significantly delayed flowering and maturity time occurrence, reduced plant height and grain yield, and increased number of branches. Reduction index (RI) correlated positively with HDS score at Terbol station in different seasons and at Marchouch in 2016–2017 seasons. Eleven tolerant accessions were identified and further evaluated to 1×, 1.5×, and 2× of recommended dose of both herbicides. The results indicated that the harmful effect of herbicides on grain yield reduction intensified from 13.4 to 27.2% and from −7.6 to 1.8% as the dose of metribuzin and imazethapyr increased respectively from 250 to 500 g a.i. ha−1 and from 75 to 150 g a.i. ha−1. Tolerance to metribuzin and imazethapyr in eight faba bean accessions was confirmed with no significant reduction in grain yield.This research was funded by CRP grain legume program from 2012–2016 and by Arab Fund for Economic and Social Development (AFESD) for the operationalization of decentralized Center in five Arab countries

Assessing the Stability of Herbicide-Tolerant Lentil Accessions (<i>Lens culinaris</i> Medik.) under Diverse Environments

Assessing the adaptability and stability of herbicide-tolerant lentil accessions to two broad-spectrum post-emergence herbicides in multi-environment trials has become a must in a breeding program to improve its selection. The adaptability and stability of 42 herbicide-tolerant lentil accessions were investigated using five stability parameters under eight different environments. Significant Genotype–Environment (GE) interaction was found for days to flowering (DFLR), days to maturity (DMAT), and seed yield per plant (SY). The analyzed stability parameters such as Cultivar superiority, Finlay–Wilkinson, Shukla, Static Stability, and Wricke’s Ecovalence ranked the tested accessions differently, confirming the importance of using a combination of stability parameters when evaluating the performance of a group of accessions. GGE biplot of the SY trait accounted for 60.79% of sums of squares of the GE interaction and showed that cool and high rainfall environments are ideal for testing the agronomic performance of tolerant accessions. The GGE biplot of SY showed that IG4605(19), IG195(6), and IG156635(12) were specifically adapted to one mega environment, whereas IG70056(38) was identified as a superior line having a high and stable yield. These lines should be included in lentil crossing programs to develop herbicide-tolerant cultivars adapted to diverse environments