Mapping QTLs for Yield Stability in Durum Wheat Grown under Different Water Regimes

Among the most important Mediterranean annual crops, durum wheat is widely grown in drought-prone areas. Therefore, improving water-use efficiency （WUE） of durum wheat represents a major breeding goal. IDu-WUE （Improving Durum wheat for Water Use Efficiency and yield stability through physiological and molecular approaches） is a collaborative project among public and private research centres in Italy, Spain and WANA （West Asia and North Africa） countries （Morocco, Tunisia, Syria and Lebanon） funded by the European Union aimed at investigating the genetic variation for WUE and yield stability in durum wheat grown in Mediterranean droughtprone areas. During the first year of the project, a number of morpho-physiological traits （e.g. early vigour, flowering time, leaf rolling, number of fertile tillers, etc.）, WUE, WUE-related traits （e.g. carbon isotope discrimination, canopy temperature, chlorophyll fluorescence, etc.）, yield and its components have been investigated in a RIL population （249 lines） and a collection of ca. 190 durum wheat accessions characterized by a high level of linkage disequilibrium （Maccaferri et al., 2005）,     

New strategies for increasing heterozygosity in crops: Vicia faba mating system as a study case

Our research assesses the feasibility of using artificial selection on pre-mating floral traits to modify the mating system of faba bean (Vicia faba). This analysis considered two synthetic populations, which were derived from different genetic pools and had undergone five years of multiplication. For these populations, we identified floral and inflorescence traits that influence outcrossing per plant and examined the relative importance of these traits in governing yield. Codominant isozyme loci and the mixed-mating model were used to estimate the multilocus female outcrossing rate. A maternal half-sib design was used to evaluate the additive genetic component of floral and inflorescence traits, yield and yield components. Multiple regression was used to assess the effects of floral and inflorescence traits on outcrossing and yield and components of yield. The two populations exhibited mixing mating. Self-fertilization appears to result from the action of pollinating bees, so that its incidence could be modified by selection on floral and inflorescence traits that affect pollination. Floral and inflorescence traits affected individual differences in outcrossing unequally, with most variation being associated with the numbers of displayed flowers and inflorescences. Variation among plants in reward traits and in shape, although statistically significant, had limited and inconsistent influences on individual differences in outcrossing. Yield and its components varied strongly with aspects of floral display and, to a lesser extent, floral design, except for seed weight. Overall, our results imply that both outcrossing and yield could be enhanced by selection for plants that produce more inflorescences, each with relatively few flowers.     

Cloning: Eight Years After Dolly

It is now 8 years since the birth of Dolly, the first animal produced by nuclear transfer using a donor cell population established from an adult animal. During this time, the technique of nuclear transfer has been successfully applied to a range of mammalian species for the production of offspring using a plethora of donor cell types derived from both foetal and adult tissues. In addition, when coupled with genetic manipulation of the donor cells, transgenic offspring have been produced with a range of genetic modifications including gene knockouts and gene knockings. Despite the apparent successes of the technology, the efficiency of development to live offspring has remained low and developmental abnormalities still occur. The objectives of this paper are to review some of the successes and failures of the nuclear transfer procedure since the production of Dolly. In particular, we will review the major steps in the procedure and discuss studies from our laboratory and others which have modified the procedure in ways which may impact on development.     

The role of crop-pollinator relationships in breeding for pollinator-friendly legumes: from a breeding perspective

Breeders are encouraged to develop breeding approaches that strive to integrate food production into the healthy functioning of agro-ecosystems. In the case of legumes, this approach should preserve bee fauna by providing suitable floral resources within the crops themselves. In parallel, legume breeding for sustainable agriculture is linked to the development of environmental services. Foraging places and nesting sites for solitary and social bees are some of the ecological services provided for legumes. Crops with floral attractiveness and rewards for insects can be used to enhance pollinator conservation as well as crop yield and yield stability. We analyze how understanding crop-pollinator relationships (CPR) can contribute to the production of high-yielding and pollinator-friendly varieties by examining: (1) The status of knowledge on mating systems and floral traits; (2) The contribution of CPR understanding to plant breeding for both hybrid-seed production and open-pollinated population improvement.     

Yield stability of faba bean lines under diverse broomrape prone production environments

Faba bean (Vicia faba L.) is one of the important pulse crops grown in many parts of the world. Its production and productivity are affected by different biotic and abiotic stresses. Broomrape (Orobanche and Phelipanche spp.) causes yield losses of 7- 80% in major faba bean growing countries mainly in the Mediterranean Basin and Nile Valley countries. Host plant resistance is found to be the most effective and economic method of broomrape control. Efforts made at the International Center for Agriculture Research in the Dry Areas over many years to develop advanced breeding lines with acceptable resistance and tolerance levels to broomrape have resulted in the identification of several useful breeding lines. These lines were shared with National Agricultural Research Systems (Egypt, Sudan, Tunisia and Portugal) as part of the Faba Bean Orobanche International Nursery, in order to test their stability across three seasons (2005, 2006 and 2007). The results showed that Orobanche plant number, dry weight, Orobanche index, flowering date, maturing date and grain yield were significantly different among lines and locations. AMMI analysis showed that some lines derived from hybrid bulk populations “HBP/DS0/2000” and “HBP/ES0/2000” showed acceptable levels of yield stability in the presence of Orobanche infections across all environments compared with susceptible check. In highly infested soils, the tolerant and resistant lines gave acceptable levels of yield compared with the susceptible check. However, the yield potential of resistant and tolerant lines in non-infested soils was lower than the highly susceptible check.     

Views on strategies for higher agricultural education in support of agricultural and rural development

Agricultural and rural development programs can only succeed if they are based on effective participation and support of actors from the policymaking stage through all levels, including field personnel and primary producers. But these actors must possess the knowledge, attitude, and skills necessary to execute their tasks. For this reason, agricultural education and training has an integral part to play in any agricultural and rural development effort. The Food and Agricultural Organization (FAO) of the United Nations has made significant contributions to the development of agricultural education in its member countries. FAO's contributions have focused on institution building, group training, and fellowship/study tours. This paper reviews some of the lessons learned through FAO involvement in these areas and recommends directions for improvement. These recommendations include the following:

1. Higher agricultural education institutions should become more involved in rural development by participating in appropriate activities leading to the formulation of national development policies.
2. These institutions should develop education programs and curricula responding to the need of development by providing the knowledge and skills required to meet the needs of the people concerned and to solve their technical and socio-economic problems.
3. More emphasis should be placed on improving the quality of teaching and on practical training.
4. The same institutions should undertake to play a leading role in the agricultural and training systems at the national level.
5. Research should be an integral part of higher educational institution programs and the research themes should include interests of small and poor agricultural producers and measurement of research impacts.
6. Regional and inter-regional collaboration among higher agricultural education institutions should be encouraged.

     

Comparison of the reaction of tomato lines to infection by tomato yellow leaf curl begomovirus in Lebanon

Tomato yellow leaf curl begomovirus (TYLCV), transmitted by the whitefly Bemisia tabaci , is epidemic in Africa, the Middle East and South-East Asia. It is also reported in some European countries and the American continent. In Lebanon, it is the major limiting factor for summer and autumn production of tomato. Comparison of the nucleotide sequence in the intergenic region with other reported leaf curl viruses showed the Lebanese TYLCV isolate to be closely related to Egyptian, Israeli and Jamaican isolates (94–96% identity). However, it is not closely related to isolates from Sardinia, Spain and Thailand, or to tomato leaf curl isolates from India, Taiwan and Australia. In field and greenhouse screening tests conducted for 5 years on 67 tomato lines, several were identified as promising. TY-Carla, PSR and RS lines were among the most promising with determinate growth, while S&G 143 and the DR lines were the most promising with semi-determinate and indeterminate growth, respectively. Virus concentrations in most, but not all, tolerant tomato lines were significantly lower than in the susceptible lines. None of the lines tested was immune to the virus. A survey of TYLCV alternative hosts on at least 58 plant species, using nucleic acid hybridization, showed that Amaranthus sp., Malva sp., Sonchus oleraceus , Plantago sp., Solanum melongena , Phaseolus vulgaris and Mercurialis annua may play an important role in the epidemiology of TYLCV in Lebanon. Mercurialis annua is a newly reported host for TYLCV.     

Summer drought and canopy opening increase the strength of the oak seedlings–shrub spatial association

? Context

The knowledge of how shrub–seedling interactions vary with summer drought, canopy opening, and tree species is crucial for adapting forest management to climate change.

? Aims

The aim of this study was to assess variation in shrub–oak recruitment associations along a south–north drought climate gradient and between two levels of canopy cover in coastal dune forest communities in a climate change-adapted forest management perspective.

? Material and methods

Mapped data of associational patterns of seedlings of three oak species with interspecific pooled shrubs were analyzed using a bivariate pair correlation function in 10 (0.315 ha) regeneration plots located in forest and recent gap sites along the climate gradient. An index of association strength was calculated in each plot and plotted against a summer moisture index.

? Results

The association strength increased with increasing summer drought from wet south to dry north and from closed forests to gaps.

? Conclusion

Consistent with facilitation theory, our results suggest that climate change may shift associational patterns in coastal dune forest communities towards more positive associations, in particular in canopy gaps. In a perspective of climate change, foresters may need to conserve understory shrubs in gaps in order to promote oak species regeneration.     

Understanding the relationships between genetic and phenotypic structures of a collection of elite durum wheat accessions

A collection of 191 durum wheat accessions representing Mediterranean Basin genetic diversity was grown in nine different environments in four countries, with productivities ranging from 0.99 to 6.78 t ha⁻¹. The population breeding structure comprised eight genetic subpopulations (GSPs) using data derived from 97 evenly distributed SSR markers. The phenotypic structure was assessed: (i) from the mean values of six agronomic traits across environments (multivariate), and (ii) from data representing each trait in each environment (univariate). Mean daily maximum temperature from emergence to heading was significantly (P < 0.05) and negatively associated to yield, accounting for 59% of yield variations. Significant but weak relationships were obtained between the genetic similarities among accessions and their overall agronomic performance (r = 0.15, P < 0.001), plant height (r = 0.12, P < 0.001), spike–peduncle length (r = 0.06, P < 0.01) and thousand kernel weight (r = 0.03, P < 0.05), suggesting a very low possibility of prediction of the agronomic performance based on random SSR markers. The percentage of variability (measured by sum of squares) explained by the environment varied between 76.3 and 98.5% depending on the trait, while that explained by genotypes ranged between 0.4 and 12.6%, and that explained by the GE interaction ranged from 1.1 to 12.5%. The clustering of the accessions based on multivariate phenotypic data offered the best explanation of genotypic differences, accounting for 30.3% (for yield) to 75.1% (for kernel weight) of the observed variation. The genotype × environment interaction was best explained by the phenotypic univariate clustering procedure, which explained from 28.5% (for kernel weight) to 74.9% (for days to heading) of variation. The only accessions that clustered both in the genetic dissimilarities tree and the tree obtained using Euclidean distances based on standardized phenotypic data across environments were those closely related to the CIMMYT hallmark founder ‘Altar 84’, the ICARDA accessions adapted to continental-dryland areas, and the landraces, suggesting that genetic proximity corresponded to agronomic performance in only a few cases.     

Breeding and genomics status in faba bean (Vicia faba)

Faba bean is an important legume crop because of its high‐yield potential and nutrition‐dense grains. There have been significant achievements in faba bean improvement in the last four decades, which led to the doubling of the global yield average. This study reviews the genetic diversity, the breeding methodologies, major achievement on biotic and abiotic traits, and the recent molecular approaches. The high genetic diversity among faba bean accessions has been useful for increasing yield potential of the crop. Substantial increase in yield potential can be gained through the development of cultivars in open pollinated conditions. In the past, many faba bean varieties that are tolerant to abiotic and biotic stresses were released worldwide. The average yield gains varied from 1.65% per year in Syria to 4.17% per year in Ethiopia. The recent advances in molecular technologies will be used to develop more coherent genetic maps, which would also facilitate assembling and ordering genomic scaffolds in a future genome‐sequencing effort and molecular‐breeding approach.