VARIABILITÉ PHÉNOTYPIQUE ET SÉLECTION DES CARACTÈRES AGRONOMIQUES DU BLÉ DUR (Triticum durum Desf.) SOUS CONDITIONS SEMI-ARIDES

Genetic improvement of agronomic traits related to yield performance and adaptation to the production environments is conditioned by the presence of phenotypic variability of the targeted characters in the plant material subjected to selection. This research was conducted to assess the magnitude of phenotypic variability, the heritability and the expected genetic gain of selection of agronomic traits in 18 durum wheat (Triticum durum Desf) varieties and segregating lines. The results showed the presence of significant variability for the measured traits. The degree of genetic determination had values greater than 70% for the duration of the vegetative phase and plant height, and below 50% for yield and aboveground biomass. The expected genetic gain ranged from 4.8% for the duration of the vegetative phase to 45.9% for grain yield. Single-character selection identified 6 desirable genotypes which brought increases of 14.9% in harvest index, 3.7 g in 1000 kernel weight, 4.8% in relative water content, and declines of 18.6% in percent cells injury, 2.1 g in yield per plant, 2.1 cm in spike length, and 12.9 grains per spike, and a gain of 1.7 spikes associated to 8.8 g of biomass. Relatively to Bousselam, the check cultivar, the selected lines brought a grain yield advantage ranging from 53.8 to 161.5%. This yield gain is associated with a desirable improvement in heat stress tolerance, and an undesirable reduction in thousand kernel weight. The study of th

DÉTERMINISME GÉNÉTIQUE DES CARACTÈRES MORPHO-PHYSIOLOGIQUES LIÉS AU RENDEMENT CHEZ LE BLÉ DUR EN ZONE SEMI-ARIDE DES HAUTS PLATEAUX SÉTIFIENS, ALGÉRIE

The present investigation was undertaken to study the inheritance pattern of morpho-physiological traits: relative water content, excised leaf water loss, flag leaf area and membrane stability, in an F3 population of durum wheat (Triticum durum Desf.). The results reflected a satisfactory range of variability in the evaluated traits. Range magnitude of the four traits represented the equivalent of 5.0 to 11.4 times the least significant difference at 5% level. Transgressors with variable frequency were observed for all the measured traits. In fact 25% of the F3 lines showed a relative water content greater than 85%, 3% has a flag leaf area superior to 26 cm², 8% had a low leaf water loss rate and 11% expressed a low electrolyte leakage rate, suggesting a high membrane stability. Medium to high broad sense heritability estimates were noted for the measured traits. Medium to high genetic gain expressed as percent of the base population mean was observed, taking the following values: 11.0%, 24.0%, 68% and 88%, for relative water content, flag leaf area, excised leaf water loss rate, and percent of cell injury, respectively. Altogether, the obtained results indicated that the studied cross population would be of interest in the breeding program and an effective progress can be made through selection of these morpho-physiological characters to enhance stress tolerance and grain yield potential

VARIABILITÉ PHÉNOTYPIQUE ET SÉLECTION DES CARACTÈRES AGRONOMIQUES DU BLÉ DUR (Triticum durum Desf.) SOUS CONDITIONS SEMI-ARIDES

Genetic improvement of agronomic traits related to yield performance and adaptation to the production environments is conditioned by the presence of phenotypic variability of the targeted characters in the plant material subjected to selection. This research was conducted to assess the magnitude of phenotypic variability, the heritability and the expected genetic gain of selection of agronomic traits in 18 durum wheat (Triticum durum Desf) varieties and segregating lines. The results showed the presence of significant variability for the measured traits. The degree of genetic determination had values greater than 70% for the duration of the vegetative phase and plant height, and below 50% for yield and aboveground biomass. The expected genetic gain ranged from 4.8% for the duration of the vegetative phase to 45.9% for grain yield. Single-character selection identified 6 desirable genotypes which brought increases of 14.9% in harvest index, 3.7 g in 1000 kernel weight, 4.8% in relative water content, and declines of 18.6% in percent cells injury, 2.1 g in yield per plant, 2.1 cm in spike length, and 12.9 grains per spike, and a gain of 1.7 spikes associated to 8.8 g of biomass. Relatively to Bousselam, the check cultivar, the selected lines brought a grain yield advantage ranging from 53.8 to 161.5%. This yield gain is associated with a desirable improvement in heat stress tolerance, and an undesirable reduction in thousand kernel weight. The study of th

DÉTERMINISME GÉNÉTIQUE DES CARACTÈRES MORPHO-PHYSIOLOGIQUES LIÉS AU RENDEMENT CHEZ LE BLÉ DUR EN ZONE SEMI-ARIDE DES HAUTS PLATEAUX SÉTIFIENS, ALGÉRIE

The present investigation was undertaken to study the inheritance pattern of morpho-physiological traits: relative water content, excised leaf water loss, flag leaf area and membrane stability, in an F3 population of durum wheat (Triticum durum Desf.). The results reflected a satisfactory range of variability in the evaluated traits. Range magnitude of the four traits represented the equivalent of 5.0 to 11.4 times the least significant difference at 5% level. Transgressors with variable frequency were observed for all the measured traits. In fact 25% of the F3 lines showed a relative water content greater than 85%, 3% has a flag leaf area superior to 26 cm², 8% had a low leaf water loss rate and 11% expressed a low electrolyte leakage rate, suggesting a high membrane stability. Medium to high broad sense heritability estimates were noted for the measured traits. Medium to high genetic gain expressed as percent of the base population mean was observed, taking the following values: 11.0%, 24.0%, 68% and 88%, for relative water content, flag leaf area, excised leaf water loss rate, and percent of cell injury, respectively. Altogether, the obtained results indicated that the studied cross population would be of interest in the breeding program and an effective progress can be made through selection of these morpho-physiological characters to enhance stress tolerance and grain yield potential

Respuesta del trigo duro (Triticum turgidum L. var. Durum) a la selección directa e indirecta en las condiciones semiáridas de Argelia

In arid and semi-arid areas, drought is an important abiotic factor that limits Durum wheat production. Identifying genotypes tolerant to drought is a challenge for plant breeders. This study aimed to evaluate the effect of direct and indirect selection on Durum wheat under rain-fed conditions in the high plains of Sétif, Algeria. Four parental varieties (Ofanto, MBB, Mrb5, Waha), three crosses (Ofanto/MBB, Ofanto/Mrb5, Ofanto/Waha) representing the F5, F6, and F7 populations, and one cultivar (Bousselm, control) were cultivated. Pheno-morpho-physiological traits were measured at the heading stage and yield and its components at grain maturity. Our results showed that the response to direct selection was reflected in a significant increase in grain yield, economic yield, and number of spikes, suggesting that grain yield may be improved using one of these characteristics as the selection criterion. Selection by canopy temperature was affected by a significant decrease in the drought susceptibility index (-11.3 %), making it possible to obtain abiotic stress-resistant lines. The study of the relationships between F5, F6, and F7 populations has shown that grain yield, economic yield, and plant height correlate with each generation, indicating no effect of genotype-environment interaction, unlike others. Late selection revealed eight meaningful lines (L1, L8, L14, L28, L32, L35, L36, and L40) in the selection process, maintaining high production throughout different cropping seasons. These successful lines were selected based on traits related to productivity: Gr.YLD, Ec.YLD, NS. These characters provide the same information as breeding programs, according to our results.En zonas áridas y semiáridas, la sequía es un factor abiótico que limita la producción de trigo duro; por tanto, la identificación de genotipos tolerantes a la sequía es un reto para los fitomejoradores. Este estudio buscó evaluar el efecto de la selección directa e indirecta en el trigo duro en condiciones de lluvia en las altas llanuras de Sétif, Argelia. Se cultivaron cuatro variedades parentales, tres cruces que representan las poblaciones F5, F6 y F7 y un cultivar (control). Los resultados mostraron que la respuesta a la selección directa se reflejó en un aumento significativo en el rendimiento del grano, el rendimiento económico y el número de espigas, lo que sugiere que es posible mejorar el rendimiento del grano utilizando una de estas características. La selección por temperatura del dosel se vio afectada por una disminución significativa del índice de susceptibilidad a la sequía (-11,3 %), lo que permite obtener líneas resistentes al estrés abiótico. El estudio de las relaciones entre las poblaciones F5, F6 y F7 ha mostrado que el rendimiento del grano, el rendimiento económico y la altura de la planta están correlacionados con estas generaciones, lo que indica que no se ven afectados por la interacción genotipo x ambiente, a diferencia de otros. La selección tardía reveló ocho líneas significativas, las cuales mantuvieron una alta producción en diferentes temporadas de cultivo. Estas líneas se seleccionaron con base en rasgos relacionados con la productividad que proporcionan la misma información que los programas de mejora, según nuestros resultados

Annual study of Leptocybe invasa gall’s number Fisher & La Salle 2004 (Hymenoptera: Eulophidae) of Eucalyptus camaldulensis (Myrtaceae) in the North-East of Algeria

Eucalyptus camaldulensis is an essence of the family Myrtaceae. It resists a certain salt content and the sea wind. Despite that, it subject to many factors of degradation as parasitic and harmful insects. In the last years, an insect is detected on the foliage of Eucalyptus  camaldulensis trees in Algeria (North-East region). The results made it possible evidence the presence of one harmful species Leptocybe invasa Fisher & La Salle 2004 (Hymenoptera: Eulophidae), this parasite has been detected in 2006, The Chronology of Gall’s emergence of Leptocybe  invasa and its field infestation rate were followed since 2010, in Eucalyptus plantation in the North-East Region. Some statistical methods of Gall’s emergence of this pest is reviewed and discussed. First, after exploration, we selected the most affected trees, second, we organized the samples of each tree, we respected the orientation (North-South-East-West). For each study site 10 trees were marked. 30 leaves of each tree were removed, so it is 300 leaves for each site, which were analyzed. We used the method of time series that connects the time with the number of galls. This study is based on the number of galls observed, on both sides of the leaves. In order to highlight the degree of attack of pests. The outputs were made from October 2012 to October 2013, due to two outputs per month. Keywords: Eucalyptus, gall wasps, Eulophidae, gall inducers, Algeria

Contribution to the study of xylophagus insects and their role in the decline of Alep pine (Pinus halepensis mill.) in El Ouldja’s Megsem forest (Setif - Algeria)

Pinus halepensis Mill., is an essence from the Pinaceae family. This importance is attributed to its economic and aesthetic values. Despite its robustness, this tree is subject to many degradation factors including, for some time, that of wood-boring insects which for the most part are fatal. The purpose of this investigation is to classify these insects, define their role in pine decline and evaluate the damage caused by them in the Megsem forest. The result of the study shows that members of the Curculionidae, Cerambycidae and Buprestidae families could be held responsible for the majority of the damage observed on the pine Keywords: Pinus halepensis, decline, Megsem, wood-boring insects, Algeri

Etude de la stabilité de quelques variétés de blé dur (Triticum durum Desf.) dans les conditions semis aride du Sétif en Algerie

Notre objectif est d’etudier la stabilité du rendement de dix genotypes de blé dur expérimentées pendant quatre ans (2009-2013) dans la région  semi-aride de Sétif.Nous utilisons au cours de cette étude trois indices de stabilité paramétriques et non paramétriques pour évaluer les  performances des génotypes. L’étude des indices paramétrique de stabilité, notamment l'écovalence de Wricke (Wi²) a montré que les génotypes  Mexicali75 (4.23) et Hoggar (11.07) sont considérés comme les plus stables parmi les génotypes testés. Alors qu'en termes d'indice de supériorité  (Pi), les genotypes Polonicum (29,61), Sooty (33,99), Altar84 (34,47) et Mexicali75 (35,37) ont les valeurs les plus faibles de (Pi). L'indice d'adaptabilité  géométrique (GAI) a montré que les génotypes Mexicali75 (42,00), Kucuk (40,26) et Altar84 (40,03) sont les plus stables. Les indices non  paramétriques Si(2), Si(3), Si(6) ont des corrélations non signifiantes avec le rendement moyen en grains. L’étude de la variabilité génotypique du  rendement en grains a montré que Mexicali75 était le génotype qui avait la plus petite variation de rendement au cours des quatre saisons.  Globalement, Mexicali75, Hoggar et Kucuk sont les génotypes très stables