Frequent episodes of heat threaten sustainable agriculture in Egypt. This study is an urgent call to select tolerant genotypes of heat and discover the predicted screening phenotypic parameters. Here, twenty spring wheat genotypes were exposed to heat stress under field conditions for screening heat tolerance. Stress environments were simulated by delaying the sowing date by 53 and 58 days than the normal environments for two successive seasons. Stressed plants received the highest peak of heat during the reproductive growth stage. Eight phenotypic parameters were measured to evaluate genotype tolerance. Mean performance, reduction percentage/trait, and heat susceptibility index parameters were calculated. Additionally, the pollen grain viability during spike emergence and the germinability of producing grains were investigated. Results demonstrated: (1) Highly significant differences ( P < 0.01 ) between genotypes, treatments and genotypes by treatments in grain yield and other traits in both studied seasons, (2) significant reduction in all studied traits compared to the non-stress environment, (3) the overall yield reduction, based on grain yield/m 2 , was 40.17, 41.19 % in the first and second seasons, respectively, and the most tolerant genotypes were Masr2, Sids1, Giza 171 and Line 9, (4) limited impact of heat has detected on pollen grains viability and germinability, and (5) grain yield as a selection criterion for heat stress remains the most reliable yardstick.

Fennel (Family Apiaceeae) is one of those strategic medicinal and aromatic plants in Egypt with great value as an economical exported plant. Fennel undergoes propagation through breeding of some fennel cultivars from different world region in order to keep out of genetic deterioration in the native Egyptian cultivars, and enrich its favorable active ingredients. The advanced plant breeding programs depend on some markers such as morphological, cytological, biochemical and molecular markers to study its genetic diversity. In this work two molecular markers ISSR and SCoT markers were used to assessment of genetic diversity among six fennel cultivars (Foeniculum vulgare Mill.) planted in Egypt; three of Egyptian origin (Balady, Elalamy and Azoricum) and the other ones are of different origin (Holland, Indian and German). The analyzed data reveals that the ISSR marker is more discriminating, provides more informative data than SCoT marker and can be reliable to evaluate the genetic diversity among the six examined cultivars as it performs the highest percentage of polymorphism 61% and higher unique bands number (4). According to ISSR molecular marker German and Indian cultivars are close distant; can exchange gene in between them smoothly despite the ultimate change in the environmental and weather conditions of their origin land. In conclusion, according to Nie , s and li , s coefficient based on SCoT marker analysis between the cultivars; Indian cultivar was quite distant from Azoricum by the same time that Azoricum is close distant to Holland, as well as; Elalamy is close distant to Balady.

Background: Bio-fertilizers as a safe alternative to the synthetic fertilizers come to the front in the agriculture requirements as they provide the planted crops with their nutrients to ensure high quality and productivity. Many of them must be screened and examined to configure their effect on the plants. Results: This study was designed to evaluate two promising bio-fertilizers: Moringa oleifera leaf extract (5.0, 10.0, 20.0%) and Sacharomyces cerevisiae aqueous extract (5.0, 10.0, 20.0%) for their safe usage on Allium cepa root meristems as a model system for monocots after 3.0 h of direct treatment. This evaluation focused on both cytogenetic and cytological levels. Cytogenetic studies screened the effect of each extract on the mitotic apparatus considering the mitotic index, mitotic phase index, percentage, and type of abnormalities. Cytological studies with transmission electronic microscope screen the effect of each extract on ultra-structural organelles (mitochondria, endoplasmic reticulum, peroxisomes, dictyosomes in addition to the vacuoles) in the cell cytoplasm. Obtained data revealed that the yeast extract shows a remarkable cytological effect on cytoplasmic organelles. By the same time, only the higher used concentration of Moringa extract shows higher chromotoxic effect on chromosomal DNA despite it shows high proliferation effect on the treated root tip cells. Conclusion: Among the two tested bio-fertilizers, the Moringa extract in lower concentration is more preferable as it does not harm neither the cytoplasmic organelles nor the mitotic apparatus.

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