Genetic Structure of Modern Durum Wheat Cultivars and Mediterranean Landraces Matches with Their Agronomic Performance

A collection of 172 durum wheat landraces from 21 Mediterranean countries and 20 modern cultivars were phenotyped in 6 environments for 14 traits including phenology, biomass, yield and yield components. The genetic structure of the collection was ascertained with 44 simple sequence repeat markers that identified 448 alleles, 226 of them with a frequency lower than 5%, and 10 alleles per locus on average. In the modern cultivars all the alleles were fixed in 59% of the markers. Total genetic diversity was HT = 0.7080 and the genetic differentiation value was GST = 0.1730. STRUCTURE software allocated 90.1% of the accessions in five subpopulations, one including all modern cultivars, and the four containing landrace related to their geographic origin: eastern Mediterranean, eastern Balkans and Turkey, western Balkans and Egypt, and western Mediterranean. Mean yield of subpopulations ranged from 2.6 t ha-1 for the western Balkan and Egyptian landraces to 4.0 t ha-1 for modern cultivars, with the remaining three subpopulations showing similar values of 3.1 t ha-1. Modern cultivars had the highest number of grains m-2 and harvest index, and the shortest cycle length. The diversity was lowest in modern cultivars (HT = 0.4835) and highest in landraces from the western Balkans and Egypt (HT = 0.6979). Genetic diversity and AMOVA indicated that variability between subpopulations was much lower (17%) than variability within them (83%), though all subpopulations had similar biomass values in all growth stages. A dendrogram based on simple sequence repeat data matched with the clusters obtained by STRUCTURE, improving this classification for some accessions that have a large admixture. landraces included in the subpopulation from the eastern Balkans and Turkey were separated into two branches in the dendrogram drawn with phenotypic data, suggesting a different origin for the landraces collected in Serbia and Macedonia. The current study shows a reliable relationship between genetic and phenotypic population structures, and the connection of both with the geographic origin of the landraces.The research was funded by the Ministerio de Economía y competitividad project AGL-2006-09226-C02-01, and Dr. Jose Miguel Soriano is funded by Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (http://www.mineco.gob.es/)

Intra- and Interclonal Variation in Anatomical Properties of Hevea Brasiliensis Muell. Arg.

The wood anatomical properties of two new rubberwood clones (RRIM 2020 [I] and RRIM 2025 [II]) at four planting densities (PDs) (500 [I], 1000 [II], 1500 [III], and 2000 [IV] trees/ha) were assessed. Fiber morphology, vessel features, and ray cell anatomy were measured. At PD I and PD II, fiber features were the highest quality. For vessel features, the highest quality was at PD I and PD IV. The moderate densities did not show substantial variation. Ray density from clone I demonstrated a direct relationship with PD because the highest value was at PD IV. Ray height showed a descending trend with increasing PD with significant differences in PD I and PD II vs PD III and PD IV in clone I. PD I showed the highest values with no significant difference compared with the others. PD in both clones did not significantly influence ray area. Some anatomical features of fiber, vessel, and ray were successfully quantified using a regression approach. The results predicted PD I as optimum for high wood quality production. Among the treatments, PD I of clone II resulted in the best quality anatomical properties

Caractérisation d'une collection de tomates issues de différentes régions du Maroc

Tomatoes are one of the most important crops in Morocco. National tomato production reached 1 231 250 tons in 2019. The sector generates thousands of jobs and is one of the pillars of the country's economy through exports. Hence, it is judicious to search for new varieties with high commercial potential. This study aimed to characterize a collection of four local tomato genotypes (‘Taliouine’, ‘Zagora’, ‘Oufella’ and ‘Cerise or Cherry tomato’) from accessions collected in different regions of Morocco, compared to two commercial genotypes (‘Campbell 33’ and ‘Rio Grande’). The analyses concerned agronomic and growth criteria, sensory criteria and physical and physicochemical criteria (humidity, pH, Brix and color). The obtained results showed a great variability between the studied genotypes. Some genotypes showed interesting performances like ‘Campbell 33’ (number of leaves per branch), ‘Rio Grande’ (number of fruits per plant), ‘Cerise tomato’ (number of fruiting branches per plant) and ‘Taliouine’ (plant height). The three genotypes with the best taste are ‘Campbell 33’, ‘Cerise tomato’ and ‘Oufella’. They also show a high intensity of red color, high skin firmness and high aroma content. Significant variations were also observed for the different physicochemical criteria. Such results will help to identify relevant criteria that can be used for varietal improvement and can also constitute basic criteria to differentiate between tomato accessions.Les tomates sont l’une des cultures les plus importantes au Maroc. La production nationale de tomates a atteint 1 231 250 tons en 2019. Le secteur génère des milliers d’emplois et constitue l’un des piliers de l’économie du pays grâce aux exportations. Il est donc judicieux de rechercher de nouvelles variétés à fort potentiel commercial. Cette étude avait comme objectif la caractérisation d’une collection de quatre génotypes de tomates locales issues d'accessions collectées dans différentes régions du Maroc (‘Taliouine’, ‘Zagora’, ‘Oufella’ et ‘Tomate cerise’), comparée à deux génotypes commerciaux (‘Campbell 33’ et ‘Rio Grande’). Les analyses ont concerné des critères agronomiques et de croissance, des critères sensoriels et des critères physiques et physicochimiques (humidité, pH, Brix et couleur). Les résultats obtenus ont montré une assez grande variabilité entre les différents génotypes étudiés. Certains génotypes ont présenté des performances importantes comme ‘Campbell 33’ (nombre de feuilles par branche), ‘Rio Grande’ (nombre de fruits par plante), ‘Tomate cerise’ (nombre de branches fructifères par plante) et ‘Taliouine’ (hauteur de la plante). Les trois génotypes les mieux appréciés pour leur goût sont ‘Campbell 33’, ‘Tomate cerise’ et ‘Oufella’. Ces derniers montrent une forte intensité au niveau de leur couleur rouge, une peau très ferme et des teneurs élevés en arômes. Des variations significatives ont été également observées pour les différents critères physicochimiques étudiés. De tels résultats aideront à identifier les critères importants qui peuvent être utilisées pour l'amélioration variétale et qui peuvent aussi constituer des critères de base pour différencier entre les accessions de tomates

Treatment of Oil Palm Wood with Low-Molecular Weight Phenol Formaldehyde Resin and Its Planing Characteristics

In line with the Malaysian government calls to turn waste into wealth, oil palm wood (OPW) is establishing itself as a potential wood substitute. However, the OPW on its own has four imperfections, i.e.: low strength, low durability, poor dimensional stability, and poor machining characteristics. Previous studies have shown that the first three imperfections were able to be solved by impregnating with low molecular weight phenol formaldehyde (Lmw-PF) through modified compreg method. But, the machining behaviour of OPW remains uncovered. A planing test was carried out to evaluate the machining characteristics of the treated OPW. For comparison purpose, another set of test for the rubberwood and untreated OPW samples were also conducted. It is acknowledged that the planing quality of the treated OPW is of equal grade to that of rubberwood. In general, the planing of the treated OPW and the rubberwood fell into the Grade I (very good), compared to Grade III (average) for untreated OPW. The treatment significantly improves the machining characteristics of OPW, adding significant improvements on the physico-mechanical properties, durability, and appearance that have been proven in the previous studies, which make it can be used as a new, high-grade alternative for solid wood material

Reduction of Formaldehyde Emission From Phenol Formaldehyde Treated Oil Palm Wood Through Improvement of Resin Curing State

Oil palm wood (OPW) has several imperfections, and impregnation with low molecular- weight phenol formaldehyde resin through a modified compreg method can practically enhance these properties. The treated OPW, however, releases a considerable amount of free formaldehyde and thus is unhealthy for the human being. To make it applicable for indoor material, formaldehyde emission (FE) should be lowered to 0.1 ppm or lower. The FE level of the treated OPW was reduced from 0.3 to 0.1 ppm or lower by improving the resin curing state through two approaches, i.e. modifying the hot pressing compression schedule during the process and adopting an extended drying after the process. It is acknowledged that the extended drying gave more effect on the FE reduction than that of modifying hot-pressing schedule. The combination pressing schedule of 12.5%®25%®50% and extended drying of 48 h emits the lowest, safe formaldehyde of 0.08-0.10 ppm, which is considered safe according to American National Standard Institute (ANSI) standard. The improving resin curing state through modifying the hot pressing schedule and adopting extended drying could be used as a practical way to reduce the FE level of the treated OPW to a safe level suitable for various furniture and indoor applications