Susceptibility of Some Tunisian Broad Bean Varieties to Injuries Caused by the Broad Bean Weevil Bruchus rufimanus in North Tunisia

This work aims to investigate for the first time the susceptibility of six Tunisian broad bean varieties: two large seeded varieties i.e. Chahbi and Mamdouh and four small seeded varieties namely Chourouk, Bachaar, Najeh and Badï, to natural field injuries caused by the broad bean weevil Bruchus rufimanus in the region of Béja. Results showed that the large seeded varieties appeared to be more infested than field ones. The infestation rates were 37 and 37.5% for Chahbi and Mamdouh, respectively, while for the small seeded varieties, infestations ranged between 29.5 and 6.5% with Badï as the less infested variety. Moreover, seed germination was considerably affected by B. rufimanus. Significant differences were observed between infested and non-infested seeds for all varieties. The highest germination reduction was obtained with Mamdouh variety with a rate of 32.98% whereas the lowest value was achieved with Chourouk variety (10.2%). In addition, results indicated that B. rufimanus larvae feedings produced significant loss in broad bean seeds weight for all studied varieties. The highest weight loss was observed for small seeded varieties Najeh and Bachaar with weight reduction of 9.67 and 9.37%, respectively

Field Assessment of the Mass Trapping Technique for the Control of the Chickpea Leaf Miner Liriomyza cicerina

This work evaluated the chickpea leaf miner Liriomyza cicerina mass trapping technique as an alternative to insecticide spraying. A trap density of 2000 per ha was used. Trials were conducted in Beja during 2015 and 2016 using Nour variety. Leaves were sampled weekly from all treated and control plots and observed under binocular microscope. Regarding the reduction in infestation at harvest, results showed reductions of 20.11 and 18.13% respectively for chemical and mass trapping treatments compared to control. Efficacy also was assessed on the basis of captures and infestations reductions compared to control, the yield and 100-seeds weight. Results showed significant difference (at P inferieur 0.05) between treatments, with 0.21 kg/m² grain yield for the control and 0.8 kg/m² for the chemical treatment and the mass trapping. Also, regarding the 100-seeds weight, it was 21.5

Efficiency of marker-assisted selection in detection of ascochyta blight resistance in Tunisian chickpea breeding lines

Ascochyta blight (AB) resistance reactions were studied in 23 chickpea cultivars, mainly advanced lines and Tunisian varieties from the Tunisian chickpea breeding program, growing both at two locations and under controlled conditions. Two co-dominant markers both associated with AB resistance were also used in this study; the CaETR marker tightly linked to QTLAR1 in combination with the SCAR SCY17590 marker linked to QTLAR2 to explore their usefulness in discriminating between resistant and susceptible chickpea genotypes. These two markers contribute efficiently in the selection of new chickpea varieties with better combinations of alleles to ensure durable resistance to AB. The advanced line V10 presenting the resistance allele for CaETR, but being still heterozygous for the SCAR17590 was characterized as resistant to moderately resistant in field studies and under controlled conditions. This line could be very useful for developing a new variety that is fixed for both resistance alleles and expresses good levels of resistance to AB in different chickpea cropping environments. These markers are very useful in assisting chickpea breeding programs, especially thanks to their robustness, their co-dominance and their utility across different genetic backgrounds

Genotype-specific Patterns of Physiological, Photosynthetic, and Biochemical Responses in Faba Bean Contrasting Pair to Salinity

To understand the salinity tolerance mechanism in faba bean contrasting pair to salinity (cv. Chourouk as sensitive and cv. Najeh as tolerant), we evaluated the effect of high salt concentration (150 mM NaCl) on the photosynthetic, physiological, and biochemical parameters at short and long term of treatment (1 and 6 days, respectively) in the seedling stage. In general, the salinity affects the growth of plants. High salinity decreased all studied parameters, especially transpiration rate (E), stomatol conductance (gs), net CO2 assimilation (A), and substomatal CO2 concentration (Ci), and dramatic changes was registered in cv. Chourouk compared to cv. Najeh. Chlorophyll contents were also affected by salinity, especially in the sensitive variety. In addition, the synthesis of osmolytes (proline) was determinate, to understand whether the osmotic adjustment is a mechanism used by cv. Najeh to tolerate salt stress. Our research suggests that cv. Najeh should be introduced in a crossbreeding program as an elite salt-tolerant germplasm

Cryptic Diversity Hidden within the Leafminer Genus Liriomyza (Diptera: Agromyzidae)

Leafminer insects of the genus Liriomyza are small flies whose larvae feed on the internal tissue of some of the most important crop plants for the human diet. Several of these pest species are highly uniform from the morphological point of view, meaning molecular data represents the only reliable taxonomic tool useful to define cryptic boundaries. In this study, both mitochondrial and nuclear molecular markers have been applied to investigate the population genetics of some Tunisian populations of the polyphagous species Liriomyza cicerina, one of the most important pest of chickpea cultivars in the whole Mediterranean region. Molecular data have been collected on larvae isolated from chickpea, faba bean, and lentil leaves, and used for population genetics, phylogenetics, and species delimitation analyses. Results point toward high differentiation levels between specimens collected on the three different legume crops, which, according to the species delimitation methods, are also sufficient to define incipient species differentiation and cryptic species occurrence, apparently tied up with host choice. Genetic data have also been applied for a phylogenetic comparison among Liriomyza species, further confirming their decisive role in the systematic studies of the genus

Exploring the Genetic Variability and Potential Correlations Between Nutritional Quality and Agro-Physiological Traits in Kabuli Chickpea Germplasm Collection (Cicer arietinum L.)

Chickpea is an important source of plant-based protein and mineral elements such as iron (Fe) and zinc (Zn). The development of superior high-yielding germplasm with high nutritional value becomes central for any breeding program. Chickpea biofortified and nutrient-dense seeds can contribute to mitigate many human health problems associated with protein and micronutrients deficiency. In this study, 282 advanced chickpea lines were grown under field conditions to evaluate their agronomic performances and nutritional quality value. The trial was conducted under winter planting conditions during the cropping season 2017/2018 at ICARDA-Marchouch research station, Morocco. Results revealed high genetic variation and significant differences between the tested genotypes for all studied parameters. Under field conditions, the grain yield (GY) varied from 0.57 to 1.81 (t.ha–1), and 100-seed weight (HSW) ranged from 23.1 to 50.9 g. Out of the 282 genotypes, only 4 genotypes (i.e., S130109, S130058, S130066, and S130157) combined both good agronomic performances (GY, HSW) and high nutritional quality (protein, macronutrients, and micronutrients). Protein content ranged from 18.9 to 32.4%. For the whole collection, Fe content varied from 31.2 to 81 ppm, while Zn content ranged from 32.1 to 86.1 ppm. Correlation analysis indicated that the studied traits were significantly intercorrelated, with negative correlation between protein content and Zn concentration. Positive correlations were observed between grain filling time (F2M) and the micronutrients Zn, Cu, and Mn and macroelements K and Mg. Low positive correlation was also recorded between Pr and Fe concentrations. No significant correlation was observed between Fe and Zn. Positive correlations observed between main agronomic and nutritional quality traits makes easy any simultaneous enhancement when combining these traits

Study of some resistance mechanisms to Orobanche spp. infestation in faba bean (Vicia faba L.) breeding lines in Tunisia

The behavior of seven faba bean breeding lines toward Orobanche foetida and Orobanche crenata infestation was examined under field, pots, and in vitro conditions and compared to reference cultivars. The breeding lines presented resistance reaction to Orobanche spp. in different experiment conditions. In infested field by O. foetida, the grain yield reduction ranged from 55.7 to 83% for the breeding lines compared to 97% for the susceptible cultivar Badï. Lines L6 and L7 were the less affected by Orobanche parasitism considering severity, number of emerged Orobanche, and yield. In pots, the number of attachments varied from .6 to 3.4 and from 1.4 to 6.4 for the breeding lines against 10.4 and 12.3 for Badï inoculated, respectively, by O. foetida and O. crenata. In Petri dish experiment, Orobanche germination reached the highest rates; 69.9 and 59.7%, respectively, with O. crenata and O. foetida for Badï. For the breeding lines, it ranged from 6.3 to 44.9% for O. crenata and from 4.8 to 40.8% for O. foetida. Moreover, all breeding lines showed low tubercles number and delay in Orobanche attachments as compared to Badï. All breeding lines, except L5, maintained an acceptable level of resistance to Orobanche species manifested by a reduced Orobanche germination rate, low Orobanche number and dry weight, delay of attachments, and higher grain production compared to Badï. L5 seems to be less resistant even it behaves better than Badï in different culture conditions. The studied breeding lines could be recommended as resistance sources or candidates for varieties registrations

Intercropping reduces Mycosphaerella pinodes severity and delays upward progress on the pea plant

Mycosphaerella pinodes is a serious pea disease of worldwide distribution. The increasing interest of sustainable tools for disease control, together with the lack of sufficient levels of genetic resistance has brought our interest in the use of intercropping as a tool for management of this disease. Effect of intercropping on M. pinodes severity was studied in field experiments performed in Spain and Tunisia, in which a susceptible pea cultivar was grown as monocrop and as two species mixed intercrop with either faba bean, barley, oat, triticale or wheat. Disease was significantly reduced in terms of both percent of diseased tissue per plant and vertical progress of lesions when pea was intercropped. Faba bean and triticale intercropped with pea showed the highest suppressive ability with above 60% of disease reduction. Oat, barley and wheat showed low to moderate M. pinodes suppressive effects. Suppressive effects can be ascribed to a combined reduction of host biomass, altered microclimate and physical barrier to spore dispersal. © 2010 Elsevier Ltd.This research was supported by EU FP6 integrated project Grain Legumes and Spanish project AGL2008-01239.Peer Reviewe