الفهرس 
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Abstract
Brassicaceae is one of the largest Angiosperm families, comprises 3977 species and 341 genera. Brassica L. is one of the most economically important genera within this family, it includes approximately 39 species worldwide. In Egypt, the genus is represented by five species among them, Brassica tournefortii Gouan.
Brassica tournefortii is a common roadside and weed of cultivations especially in the Nile Delta, in the western desert, and western Mediterranean strip. The preliminary field study in Egypt, during this work, indicated that the field and herbarium showed that this species has considerable phenotypic plasticity. Taxonomically this species possesses debates at its infraspecific level worldwide including Egypt. To date, no detailed studies treated this species at infraspecific in Egypt to clarify its taxonomic identity, the extent of its morphological plasticity in relation to soil factors (environmental), molecular factors (genetic), in addition to, trace if these variations reflected on seed and pollen grain sculpture, as well as anthers mycoflora. This work was carried out to deduce the factors delimiting the infraspecific spatial distribution and their relation to its associate ecto-mycoflora.
This taxonomic revision was carried out based on macro-morphological, seed, and pollen sculpture as micro-morphological characters using Scanning Electron Microscope (SEM), for 27 populations, representing the different geographical range of the species, in addition to the herbarium specimens. The current study used 70 morphological characters, revealed the grouping of the studied 27 populations into five distinct Forms (1, 2, 3, 4 & 5). These forms mainly depending on the shape of radical leaves with special reference to the terminal lobe and fruit characters.
The seed coat sculpture is a delimiting character, which has been used successfully to distinguish the different identified five Forms (F1-F5). SEM of the seed sculpture of the identified B. tournefortii five Forms distinguished them into three patterns including papillate (Forms 3, 4 & 5), reticulate (Form 1), and Form 2 distinguished by reticulate-foveolate pattern.
This work on pollen grains is a pioneer at the infraspecific taxa (Forms, F1-F5) of B. tournefortii. The retrieved data revealed that the pollen grains are reticulate, tricolpate, heterobrochate type. Based on pollen shape the studied Forms (F1-F5), were grouped under two shapes subprolate (Forms 1, 2 & 3) and prolate (Forms 4 & 5). The exine of the five Forms showed inter-form variations, as the reticulum lumen size decreased in width from Form 5, 3, 2, 1 & 4, in descending pattern. The pollen grain micro-features indicating its taxonomic value at the infraspecific level. The P/E ratio of the identified forms grouped them into two groups comparable to that based on the morphology, where P/E in Forms (1 and 3) ≤ 1.32 and Forms (2, 4, and 5) < 1.32.
Soil analysis was carried out using fifteen physical and chemical characters of the soil supported the studied 27 populations (grouped morphologically into five Forms (F1-F5). The results showed that these Forms grow in sandy loam soil, moderately alkaline soil, tolerate calcium and magnesium, and are susceptible to salinity. The field and herbarium data revealed the co-distribution of the five identified Forms (F1-F5), along their geographical range. This co-distribution is confirming the low influence of the environmental parameters (the fifteen studied soil parameters) on the spatial distribution of the morphological identified Forms of B. tournefortii in Egypt.
Application of cluster analysis to the data retrieved from the usage of the five selected ISSR primers on the five morphologically identified B. tournefortii Forms (F1-F5), revealed three clades, reflecting close genetic relationships between Forms (4 and 5; 86% similarity) and between Forms (1 and 3; 83% similarity), while Form 2 is in a separate distal clade. These molecular results are compatible with that obtained from the cluster analysis of the morphological results. No intermediate forms were traced in both recent and old studied populations. This result reflects considerable genome stability of B. tournefortii five forms in Egypt since 1908 (the time of the species record). Now, we can conclude that the morpho-plasticity of the studied species is a genetically controlled issue. The genetic relationships between the identified Forms were detected and documented.
This work is a pioneer to study the anther ecto-mycoflora of B. tournefortii infraspecific Forms (F1-F5). The retrieved data revealed the presence of six fungal species namely: Alternaria alternata, Cladosporium oxysporum, C. tenuissimum, Penicillium chrysogenum, P. citrinum, and P. raistrickii. Alternaria alternata distinguish Forms (2 and 5) from the other Forms; where no fungal species isolated from Form 1 and Cladosporium oxysporum present in Form 4 and not detected in Form 3. Accordingly, we can deduce that the detected anther ecto-mycoflora can be used to delimit the morphologically identified forms.
We can conclude that the importance of the multidisciplinary approach to assess the taxonomic identity of the infraspecific taxa especially in species with notable morpho-plasticity.
Finally, our suggestions for future research:
1) To grow plants of the five Forms in a common garden and under controlled conditions (e.g., a gradient of salinity, pH, etc.) to document to what extent the variation observed is constant and how much plasticity is there in each form.
2) Study the factors controlling the differences in anther mycoflora among the five forms.