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In this study we aimed at elaborating the contribution of sunflower stomata on both sides in the stomatal conductance (gs) and the relation between its regulation and specific aquaporins expression under different conditions. Our results indicated higher stomatal index of the adaxial than the abaxial as well as the photosynthesis (A), manifesting that stomatal index was a key factor for A and/or stomatal conductance (gs). Sunflower plants could absorb CO2 from both leaf surfaces and therefore have a more efficient photosynthetic CO2 uptake and fixation rates than other C3 species maintaining the high concentration of intercellular CO2. We also indicated that stomatal regulation rather than stomata per se determines the rate of transpiration (E). Key regulators of stomata are plant vacuoles in which aquaporins (TIPS) function. Insilico characterization of sunflower TIPS deduced from database indicated a conserved motif MIP with other species proved to transport water and involved in many different physiological processes. Inconsistent regulation of TIPs under different conditions was detected indicating TIPs were not involved in stomatal regulation at these conditions. Hierarchical analysis showed that TIP7 was distantly related to the other sunflower identified aquaporins.

Eragrostis Wolf is considered one of the largest genera of family Gramineae (Poaceae). It is a cosmopolitan genus and represented in Egypt by 14 taxa. The species limits are often overlapping due to the wide range in variation within this genus. So, it is difficult to establish specific boundaries and diagnostic characters. The main goal of this work is to establish the limits and the diagnostic characters in the Egyptian taxa, using cluster analysis and principal coordinates analysis based on morphological characters. Interactive keys have been designed as an aid for online identification and looking for diagnostic characters. The morphological characters of Inflorescence, spikelets, panicle, glumes, palea keels and caryopsis are very important and necessary in the identification of the studied species. The results of coordinate analysis as well as UPGMA dendogram revealed that Egyptian Eragrostis species can be divided into 3 groups: group (A) includes: E. minor and E. cilianensis; group (B) includes E. tef, E. tenuifolia, E. sarmentosa, E. barrelieri, E. aegyptiaca and E. pilosa while group (C) includes E. aspera, E. ciliaris, E. japonica, E. lepida, E. tenella, and E. tremula. More research is needed to confirm the occurrence of several taxa in Egypt, such as Eragrostis purpurascens and E. nitida, which have been reported in some publications but are uncertain.

Saint Katherine protectorate is one of the most floristically diverse spots in the Middle East. A field surveys, as well as critical revision of herbarium specimens, were carried out during 2013-2020 revealed that 430 taxa belonging to 283 genera and 62 families. The life-forms are classified into seven life forms with dominance of Therophytes (39%) followed by Chamaephyte (24.7%). Chorological study indicated that 52% of recorded taxa were mono-regional native to Saharo – Arabian (29%), Irano- Turanian (10.39%), Mediterranean (7.4%), Sudanin (4%) while tropical and sub- tropical represented by (0.2%) only. 223 taxa were mono-regional, 127 taxa were bi-regional, while 16 taxa were endemic and Steno-endemic. Investigated taxa distributed in four microhabitats; terraces, slopes, gorges, and wadi bed the last two were the most diversity. The present study investigated that presence of Papaver somniferum is a new record to flora of Egypt, eight new records to Sinai and thirty four new records to the study area.

Seven sites were surveyed for collecting samples of C4 and C3 plants of Poaceae family from aquatic and terrestrial habitats. C4 plants include Saccharum sp., Saccharum spontaneum, Echinochloa stagnina, Echinochloa colona and Echinochloa crusgalli. C3 plants include Phragmite australis and Leersia hexandra. Morphological description and anatomical characteristics of culm and leaf were studied in the two habitat. Growth rate and anatomical features of studied species affected by altering habitat from aquatic to terrestrial habitat. Morphological and anatomical characters were recorded and the data were analyzed using Past Software V. Cluster analysis was done depending on morphological characters and anatomical characters separately. The relationship between the studied species depending on morphological characters different from that based on the anatomical characters. Also, the relationship between studied C3 and C4 species affected by altering the habitat from aquatic to terrestrial one.

The flora of Masalata Natural Reserve (MNR) in the north-Western section of Libya, 90 km east of the city of Tripoli was surveyed in terms of life forms and phytogeography. Distribution and abundance values of the recorded species were determined. A total 445 of flowering plants are identified, they are distributed in 249 genera and belonging 64 Families. Annuals are predominated life form (60.9%), while parasites are the lowest (0.22%). The mono-regional Mediterranean species constitute 62.02% of the other flora. Species which are primarily Mediterranean but in some cases bi-regional with 30.78% and pluri-regional account for 14.38%.

Saint Katherine Protectorate (SKP) hosts 24% of Egyptian Silene species including the endemic ones. This study investigated five Silene species representing 17% of all Egyptian Silene; three of them are endemic to Egypt (S. oreosinaica, S. leucophylla, and S. schimperiana). S. schimperiana was widely distributed in different areas in SKP, whereas S. oreosinaica was very rare and was spotted as two or three populations restricted to one habitat. Moreover, S. oreosinaica has not been recorded before this study since 1983. Phylogenies based on pollen micromorphology as well as on molecular data were constructed in order to describe the evolutionary relationship among these species leading to their distribution. Although phylogeny based on the pollen grain characteristics was resulted in the separation of Silene species into two groups, the first one included S. odontopetala subsp. congesta Boiss and S. oreosinaica with sub-clade included S. schimperiana and the second group included S. linearis and S. leucophylla, there was no obvious relationship among these species in the light of their distribution. Neighbor-joining (NJ) and unweighted pair group method with arithmetic mean (UPGMA) phylogenies showed that Silene species were divided into three clades; the first one included S. oreosinaica and S. odontopetala, which were closely related; the second one included S. schimperiana and S. linearis; and the last clade had S. leucophylla. According to NJ phylogeny and principal coordinate analysis (PCoA), S. schimperiana has recent, evolutionary characters that could make it distantly related to the other species, suggesting that its wide distribution could be attributed to the adaptation of its genetic constitute to different conditions.

The present work is addressed photosynthetic rate, growth rates and quantification of aquaporin genes expression on sunflower plant to examine the expression and regulation profiles of some aquaporins, their role in regulating water transport during salt stress and their role in improving plant tolerance to stresses. The differential regulation of aquaporins might contribute to increased resistance/susceptibility to a specific stress, in a species-specific way. Aquaporins fine regulation helps plants maintain a positive water balance under detrimental environmental conditions. Both down- and up-regulation of aquaporin expression leading to changes in membrane permeability have been described and proposed to be beneficial for plants experiencing water deficit. Plants may decrease the water permeability of their cell membranes to avoid excessive loss of water from the root to the soil and / or aquaporins might play a role in stress avoidance by enhancing root water uptake, when the water potential gradient between soil and root xylem is still favorable. The contribution of both types of responses may depend on the plant species, the intensity and duration of the stress and aquaporin isoform. The salt tolerance is a complex trait but might be partly due to the expression of stress-inducible aquaporin isoforms. The plant shows different expression level of PIP1;5, PIP2;1, PIP2;3, TIP1;1 as well as different water transport activity.

This study investigates the suitability of aquatic habitats to the growth of some Poaceae C3 and C4 members. Also, the phylogenetic relationship among these species was evaluated. Seven species were collected from aquatic and terrestrial habitats. Growth rate was higher in the C4 than in the C3 species in both habitats. Growth rate of the C4 species and Leersia hexandra (C3) was higher in the aquatic than in the terrestrial habitat. Water use efficiency (WUE) was not limiting to the growth of the C4 species in both habitats. However, high WUE could positively affect growth of the C4 compared to the C3 species in both habitats. The C4 species had not only higher photosynthetic efficiency (photosynthetic rate/Rubisco ratio, nitrogen use efficiency) than the C3 species but also this efficiency increased in the aquatic habitat. Aquatic conditions did not limit stomatal conductance (gs) in the C4 species and L. hexandra. In the aquatic C4 species, the increase in gs could lead to an increase in photosynthetic efficiency and growth rate. In the aquatic L. hexandra (C3), the increase in gs and Rubisco could enhance photosynthetic rate, but resulting in a decrease in photosynthetic efficiency compared to the C4 species. The accumulation of internal CO2 and sugars along with the increase in Rubisco may suggest that the C3 species had a limited growth rate compared to the C4 species even in the aquatic habitat. Aquatic habitats could be optimum to the growth of these C4 species.

Zea mays L. is less tolerant to drought than Sorghum bicolor L. In the present study, we investigated the response of both plants to drought stress applied under field conditions by withholding water for 10 d. The plant growth in terms of shoot fresh and dry masses was more severely reduced in maize than in sorghum, consistently with reduction of leaf relative water content. Gas exchange was also more inhibited by drought in maize than in sorghum. The water use efficiency (WUE) of maize fluctuated during the day and in response to the drought stress. In contrast, sorghum was able to maintain a largely constant WUE during the day in the well-watered plants as well as in the stressed ones. Studying the expression of four aquaporin genes (PIP1;5, PIP1;6, PIP2;3, and TIP1;2) revealed that PIP1;5 in leaves and PIP2;3 in roots were highly responsive to drought in sorghum but not in maize, where they might have supported a greater water transport. The expression pattern of PIP1;6 suggests its possible role in CO2 transport in control but not droughty leaves of both the plants. TIP1;2 seemed to contribute to water transport in leaves of the control but not droughty plants. We conclude that PIP1;5 and PIP2;3 may have a prominent role in drought tolerance and maintenance of WUE in sorghum plants.

This study aimed at determining the role of aquaporins (AQPs) in the anisohydric behavior of sunflower. Deactivation of AQPs by mercury revealed that they could play vital role in the stomatal regulation and this role was not time-dependent under the control conditions. Sunflower seedlings were exposed to drought or to osmotic or ionic factor of NaCl and KCl. Under control and optimal conditions, sunflower leaves behaved in an anisohydric manner (maintaining high stomatal conductance (gs) at 13:00 compared to 9:00). At 13:00: 1) the upregulation of PIP1;1 could improve the mesophyll conductance to CO2, leading to enhancement of the photosynthetic rate (A) and consequently increasing the gs and 2) PIP2s were downregulated in the leaves, perhaps to decrease the hydraulic conductance and control excess water loss via transpiration but at the same time these genes were upregulated in the roots to improve root to leaf hydraulic conductance and maintain the positive water balance of the whole plant. Under drought, the decrease in gs and A at 13:00 could imply a shift towards near-isohydric behavior. The downregulation of PIP1s and further downregulation of PIP2s could indicate their involvement in this shift by decreasing CO2 permeability and avoiding the possible loss of water from the plant roots to soil, respectively. The anisohydric behavior of leaves treated with KCl, but not NaCl, (25 or 150 mM) could be due to the positive impact of K+ on stomata and the regulation of PIP1s and PIP2s. The anisohydric behavior could be achieved by a synchronized regulation of leaf and root AQPs.

A survey was made to record the most of common weeds in the study area as well as the dominant, associated and rare species. Five sites were selected for this survey, random sample of weeds, fixing and making herbarium sheets for these weeds and deposited them in Herbarium of Botany Department, Faculty of Science, DamiettaUniversity. Furthermore, the characteristics of the soil were these weeds growing in the orchards of new Damietta were analyzed. The most habitat types in the study area were namely, orchards, sandy fertile cultivated lands, banks of irrigation canals, reclaimed lands and waste lands. 60 wed species related to 23 families most of them are annuals, some hemicrytophytes and few perennials. The recorded species were formed monocots and dicots, with Poaceae(13 species) was the most represented family followed by Asteraceae(10 species). Chorological analysis of the recorded species indicated that the Mediterranean weed species extending into the Euro-Siberian territory attained higher occurrence in the study area as compared to those species with Saharo indian extension. Shannon and Simpson diversity index of site П was the most diverse site while the least diverse was site Ш. It's mean that there variety of species in site П compared with the rest of sites so, thus means that this site is a suitable field for growing a high no. of species. The most important soil variables controlling the distribution and richness of weed species were: soil texture, porosity, water-holding capacity, organic carbon, conductivity, calcium carbonates, chlorides and potassium, sodium and calcium cat ions. Soil pH, water holding capacity, calcium carbonates and soil bicarbonates as the best set of predict or variables of the weed species distribution in the study area. The obtained results will be useful for the determination of weeds of national significance. This approach was used to focus on the key species and make an extensive research on them. Most of these weeds remain significant problem at orchards and field crops. Results will be useful for optimum management of the noxious weeds in orchards.

Clinopodium serpyllifolium subsp. barbatum (Lamiaceae) and Datura ferox (Solanaceae) have been recorded for the first time from Egypt. Both taxa were found in the mountainous region of Saint Katherine Protected Area, South Sinai. Morphological description and photos were given. Herbarium voucher was kept at related Herbaria.

Zea mays L. is less tolerant to drought than Sorghum bicolor L. In the present study, weinvestigated the response of both plants to drought stress applied under field conditions bywithholding water for 10 d. The plant growth in terms of shoot fresh and dry weights was moreseverely reduced in maize than in sorghum as a result of drought stress, consistently with reductionof leaf relative water content (RWC). Gas exchange was also more greatly inhibited by drought inmaize than in sorghum. As a result, the water use efficiency (WUE) of maize was fluctuatedaccording to the time point during the day and in response to drought stress. In contrast, sorghumwas able to maintain largely constant WUE during the day in the well-watered plants as well asunder drought stress. This may indicate that sorghum was more efficiently controlled its waterstatus in particular water uptake than did maize. Studying the expression of four aquaporin genes(PIP1;5, PIP1;6, PIP2;3 and TIP1;2) revealed that most of the genes responded weakly to droughtstress except PIP2;3 which was highly responsive to drought in sorghum but not in maize roots,where it may have supported greater water uptake in sorghum, and thereby maintained higher leafRWC in sorghum than in maize and hence could account at least in part for the drought toleranceof sorghum as compared to maize. The outcome of this study is that PIP2;3 may have role indrought tolerance and maintenance of the WUE of sorghum plants compared to those of maize.

The cultivated varieties and landraces of Cucurbitaceae growing in Egypt are presented, 27 taxa, belonging to three genera, six species, and five subspecies. These characters are arranged according to their usefulness for identifications as follow: fruit characters, seed characters and trichome type. Fruit characters are a good taxonomic tool at varietal level when combined with the other vegetative characters. Two keys to 27 cultivated varieties of Cucurbitaceae (Cucumis, Cucurbita and Luffa) were constructed using the DELTA software system. One key is used for identification, and then the other is used as a confirmatory key. Those keys were built using 36 morphological characters include vegetative, floral, fruit and seed characters. There is a significant correlation between seed size and growth parameters. The growth parameters of the studied taxa included leaf length/size, petiole length and corolla length. There is a highly positive, significant correlation between seed volume and leaf size (r = 0.81831, P ≤ 0.001), seed volume and petiole length (r = 0.79112, P ≤ 0.001), seed volume and leaf length (r = 0.83566, P ≤ 0.001), and seed volume and corolla length (r = 0.59108, P ≤ 0.001).