BackgroundThe ability of maize populations/landraces to tolerate drastically extreme environments over the past four centuries in Algeria leads to characterize these genetic resources for germplasm management as well as the identification of the best landraces useful for genetic improvement. Thus, the aim of the present work was a fingerprinting of an Algerian maize collection (47 landraces) from Saharan oasis by using 24 agro-morphological traits and18 Simple Sequence Repeats to evaluate genetic diversity and population structure.ResultsPhenotypic traits showed large significant variation in which earliness, plant size, ear and kernel features and crop yield appeared the most discriminant traits among landraces by using principal component analysis (PCA). One hundred ninety-seven different alleles were detected with a high mean number of allele per locus (10.9). The selected SSR were highly informative with PIC values > 0.65 as well as an overall genetic diversity (0.47) highlighting a broad genetic variability in the analyzed landraces. Genetic structure analysis revealed a high genetic differentiation among the 47 maize landraces with an overall Fst value (0.33). Cluster analysis for morphological traits as well as for SSR markers grouped the 47 Algerian populations regardless their geographic origin.ConclusionsMaize from Algerian desert harbors a wide genetic diversity offering a source of novel/unique alleles useful for maize breeding programs to face the ongoing and future major challenge, the climate changes.Electronic supplementary materialThe online version of this article (10.1186/s12863-018-0655-2) contains supplementary material, which is available to authorized users.

Nitrogen use efficiency (NUE) is a complex trait of great interest whose improvement represents a strategy to maintain high crop yield reducing N-supply. We report the transcriptomic analysis of four NUE-contrasting eggplants to identify key genes related to the NUE in root and shoot, after short- and long-term low-N exposure. Differentially expressed genes involved in the light harvested complex and receptor, an oxidoreductase Ferredoxin--NADP leaf chloroplastic isoform together with the transcription factor WRKY33 and a catalase are detected in the high NUE genotypes.These genes were adopted as baits for a Co-expression Gene Networks analysis enabling to identify genes of the same expression trends. Interestingly, we demonstrated that WRKY33 upregulation triggers a higher expression of 21 genes cluster including other TFs, many of which related to N-metabolism, able to improve both NUE components. An independent de novo experiment to validate the significant highest WRKY33 expression and its gene cluster in the high NUE genotypes is carried out. Finally, a 35S::AtWRKY33 over expressing Arabidopsis transgenic line, that shows a more competitive root system more efficient to take up N from the soil, confirmed the pivotal role of WRKY33 for NUE improvement.

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Over the past decades, a growing interest in allelopathy has been recorded due to the effective use of allelochemicals as growth regulators, bioherbicides, insecticides, and antimicrobial crop protection in the sustainable agriculture field. So far, the genetic aspects of the allelopathic effects have been poorly studied, and the identification of allelopathic genes and/or genomic regions (QTLs) has become a challenge to implement specific breeding programs. Here, we review the recent genetic and genome-based research findings in allelopathy, with a particular emphasis on weed control, which is one of the major crop yield-limiting factors. We discuss the key plant–microorganism interactions, as well as including the cross-kingdom RNAi phenomenon and the involvement of microRNAs in allelopathy. Through this review, we wanted to lay the foundation for advancing knowledge in allelopathy and uncover the areas where research is needed.