Unravelling the relationship between adaptation pattern and yield formation strategies in Mediterranean durum wheat landraces

Understanding the environmental and genetic factors behind the adaptation of landraces to different environments may help design breeding strategies and to promote yield improvement. Based on previous results that showed a differential frequency of alleles associated with important agronomic traits in landraces that originated in the east (EM) and the west (WM) of the Mediterranean Basin, this study analysed their patterns of adaptation and the influence this adaptation has on yield formation strategies. Thirteen and thirty-one genotypes selected according to their membership coefficient (q>0.900) from the EM and the WM genetic subpopulations, respectively, were tested during six crop seasons under rainfed Mediterranean conditions. Yearly yields ranged from 3173 to 4917 kg/ha. EM landraces showed more spikes per unit area, while WM ones showed consistently taller plants, larger cycle length to anthesis, a shorter grain filling period, a higher grain filling rate and heavier grains. The contrasting pattern of adaptation of the two subpopulations was based on a differential ability to use the water available before and after anthesis. The yield of EM landraces, originated in the warmest and driest area of the Mediterranean basin, relied mostly on water input before anthesis, which was beneficial for spike production and for the accumulation of water-soluble carbohydrates in the stems prior to anthesis, to be remobilized to grains during grain filling. WM landraces performed better in environments with high water input during grain filling, which was efficiently used to increase grain setting and produce heavy grains. EM landraces could be used in breeding to improve the adaptation of modern varieties to terminal drought.info:eu-repo/semantics/publishedVersio

Pasta-Making Quality QTLome From Mediterranean Durum Wheat Landraces

In order to identify genome regions related to pasta-making quality traits, association mapping (AM) was performed in a set of 165 durum wheat landraces from 21 Mediterranean countries. The collection was genotyped using 1149 DArT markers and 872 of them with a known genetic position were used for AM. The collection was grown in north-east Spain during 3 years. Results of ANOVA showed that trait variation for quality traits, except for grain protein content (GPC), was mainly explained by genetic effects. Landraces showed higher GPC than modern cultivars but lower gluten strength (GS). Modern and eastern landraces showed the highest yellow color index (YI). Balkan landraces showed the lowest test weight (TW). A total of 92 marker-trait associations were detected, 20 corresponding to GS, 21 to GPC, 21 to YI and 30 to TW. With the aim of detecting new genomic regions involved in grain quality, the position of the associations was compared with previously mapped QTL by a meta-QTL analysis. A total of 249 QTLs were projected onto the same map used for AM, identifying 45 meta-QTL (MQTL) regions and the remaining 15 QTLs as singletons. The position of known genes involved in grain quality was also included, and gene annotation within the most significant regions detected by AM was carried out using the wheat genome sequence

Utilidad de los recursos genéticos en mejora: potencial de las variedades tradicionales de trigo duro de la cuenca mediterránea para la mejora de la calidad y el valor agronómico en relación a su origen geográfico

En aquesta Tesi Doctoral es va estudiar el potencial de varietats tradicionals de blat dur per a la millora de la qualitat i el valor agronòmic en base a una col•lecció de 172 accessions procedents de 21 països mediterranis. Com a referència es va utilitzar un conjunt de 20 varietats modernes representatives de la variabilitat cultivada a la zona. Els assaigs de camp es van dur a terme en secà durant tres anys a Gimenells (Lleida). Es va estudiar la variabilitat existent a la col•lecció per a les principals característiques agronòmiques i de qualitat, la presència d’estructures geogràfiques i l’efecte del clima prevalent als països d’origen de les varietats sobre llur comportament agronòmic. Es va analitzar la relació existent entre la força del gluten i la composició al•lèlica en cinc loci de glutenines d’alt (HMW) i baix (LMW) pes molecular i es van identificar noves fonts d’al•lels potencialment interessants per la millora de la qualitat.En esta Tesis Doctoral se estudió el potencial de variedades tradicionales de trigo duro para la mejora de la calidad y el valor agronómico en base a una colección de 172 accesiones procedentes de 21 países mediterráneos. Como referencia se utilizó un conjunto de 20 variedades modernas representativas de la variabilidad cultivada en la zona. Los ensayos de campo se llevaron a cabo en secano durante tres años en Gimenells (Lérida). Se estudió la variabilidad existente en la colección para las principales características agronómicas y de calidad, la presencia de estructuras geográficas y el efecto del clima prevalente en los países de origen de las variedades sobre su comportamiento agronómico. Se analizó la relación existente entre la fuerza del gluten y la composición alélica en cinco loci de gluteninas de alto (HMW) y bajo (LMW) peso molecular y se identificaron nuevas fuentes de alelos potencialmente interesantes para la mejora de la calidadA collection of 172 durum wheat landraces from 21 Mediterranean countries was assembled and used to examine their value for quality and field performance improvement in breeding programs. A set of 20 representative modern varieties were used for comparison. Field experiments were conducted during 3 years under rainfed conditions in northeastern Spain. The existing variability for the main quality and agronomic traits, the presence of geographic structures as well as the effect of the climate in the countries of origin on the agronomic performance were investigated. The relationship between gluten strength and the allelic composition at five glutenin loci was assessed, and donors of potentially novel alleles for quality improvement were identified

Association mapping of candidate genes for drought tolerance in Mediterranean durum wheat landraces

Treball al que se li ha concedit el premi al millor póster del congré