Head of Genetics Department, Faculty of Agriculture, Kafrelsheikh University, Egypt. Address: Department of Genetics, Faculty of Agriculture, Kafrelsheikh University, 33516, Egypt
Two naturally growing symbiotic N2-fixing Rhizobia coded as Vs1 and Vc1 from active root nodules ... more Two naturally growing symbiotic N2-fixing Rhizobia coded as Vs1 and Vc1 from active root nodules of Vicia sativa and V. cinerea as wild plants were isolated, respectively. Cultures of both Rhizobium isolates were purified and used for inoculation of certain differentiated legume hosts. Nodulation test indicated successfully formation of active root nodules onViciafaba and Pisumsativumcultivatedin germination tubes containing Hoagland's medium (Nitrogen free) under sterilized conditions. Rhizobium isolates were re-isolated from both host plants and their characteristics were in vitro investigated. Based on their morphological, cultural and biochemical properties, both Rhizobium isolates of Vs1 and Vc1were found to have similar characteristics of the reference strain Rhizobium leguminosarumbiovarviciae. To evaluate nitrogen fixation, efficacy of both isolates in comparison with the reference strain to form root nodules on faba bean and pea plants in Leonard’Jars was also tested. R...
Genetic diversity of cultivated soybean is very narrow. This may threaten the ability of breeders... more Genetic diversity of cultivated soybean is very narrow. This may threaten the ability of breeders to sustain improvement and increase vulnerability of the crop to yields. The objective of this research was to assess genetic diversity of six genotypes i.e., Giza 21, Giza 22, Giza 111, Crawford, Toano and line H30 by morphological and molecular markers using Inter Simple Sequence Repeats (ISSR) markers, to use this information in soybean future breeding programs. Eleven ISSR primers were tested and six of them amplified clear and reproducible bands. A total of ISSR fragments were detected, of which (65.7%) were polymorphic. Based on morphological and molecular analysis the four cultivars Giza 21, Giza 22, Giza 111 and Crawford have low genetic diversity and clustered in one group. Only Toano cultivar was positioned in another group. Moreover, the line H 30 as a promising genotype was highly diverged from other genotypes. It seems to be using Toano and line H30 as distinct and exotic g...
We investigated phylogeography of Larix sukaczewii and Larix sibirica using nucleotide variation ... more We investigated phylogeography of Larix sukaczewii and Larix sibirica using nucleotide variation at three following nuclear gene regions: 5.8 S rDNA including two internal transcribed spacers (ITS), cinnamyl alcohol dehydrogenase (CAD), and phytochrome-O (PHYO). We also included sequences of the 4-coumarate: coenzyme A ligase (4CL) gene region obtained in our recent study. CAD and PHYO showed very low nucleotide variation, but ITS and 4CL had levels of variation similar to those reported for other conifers. Pleistocene refugia have been hypothesized to exist in the Southern Urals and South Central Siberia, where four out of nine of the investigated populations occur. We found moderate to high levels of population differentiation (F ST = 0.115 – 0.531) in some pairwise comparisons suggesting limited gene flow and independent evolution of some refugial populations. In L. sukaczewii, low levels of differentiation were found among populations from areas glaciated during the Pleistocene, indicating their recent origin. Our results also suggest these populations were created by migrants from multiple, genetically distinct refugia. Furthermore, some haplotypes observed in populations from previously glaciated areas were not found in putative refugial populations, suggesting these populations might have contributed little to the extant populations created after the Last Glacial Maximum. Some authors regard L. sukaczewii and L. sibirica as a single species, while others consider them as separate species. The observed conspicuous differences in haplotype composition and distribution between L. sukaczewii and L. sibirica, together with high values of F ST between populations of the two species, appear to support the latter classification.
Larch (Larix Mill.) is one of the most widely distributed tree genera in Eurasia. To determine po... more Larch (Larix Mill.) is one of the most widely distributed tree genera in Eurasia. To determine population structure and to verify classification of five species and three varieties of the Eurasian Larix species, we investigated levels and patterns of nucleotide variation of two nuclear gene regions: the 4-coumarate coenzyme A ligase (4CL) and the coumarate 3-hydroxylase (C3H). In the 4CL region nucleotide diversity at silent sites (πsil) varied between 0.0020 in L. gmelinii to 0.0116 in L. gmelinii var. japonica and in the C3H region between 0.0019 in L. kaempferi to 0.0066 in L. gmelinii var. japonica. In both gene regions statistically significant population differentiation (FST) was detected among adjacent refugial populations of some species suggesting limited gene flow and/or long time isolation of some refugial populations. On the other hand, populations of L. sukaczewii from northwestern Russia, which was glaciated 20,000 years ago showed no differentiation. This result is consistent with recent postglacial origin of these populations. Haplotype composition of some of the investigated Eurasian Larix species suggested that they are considerably diverged. Some haplotypes were unique to individual species. Our results indicate that more intensive sampling especially from known refugial regions is necessary for inferring correct classification of Eurasian Larix species and inferring their postglacial migration.
Two naturally growing symbiotic N2-fixing Rhizobia coded as Vs1 and Vc1 from active root nodules ... more Two naturally growing symbiotic N2-fixing Rhizobia coded as Vs1 and Vc1 from active root nodules of Vicia sativa and V. cinerea as wild plants were isolated, respectively. Cultures of both Rhizobium isolates were purified and used for inoculation of certain differentiated legume hosts. Nodulation test indicated successfully formation of active root nodules onViciafaba and Pisumsativumcultivatedin germination tubes containing Hoagland's medium (Nitrogen free) under sterilized conditions. Rhizobium isolates were re-isolated from both host plants and their characteristics were in vitro investigated. Based on their morphological, cultural and biochemical properties, both Rhizobium isolates of Vs1 and Vc1were found to have similar characteristics of the reference strain Rhizobium leguminosarumbiovarviciae. To evaluate nitrogen fixation, efficacy of both isolates in comparison with the reference strain to form root nodules on faba bean and pea plants in Leonard’Jars was also tested. R...
Genetic diversity of cultivated soybean is very narrow. This may threaten the ability of breeders... more Genetic diversity of cultivated soybean is very narrow. This may threaten the ability of breeders to sustain improvement and increase vulnerability of the crop to yields. The objective of this research was to assess genetic diversity of six genotypes i.e., Giza 21, Giza 22, Giza 111, Crawford, Toano and line H30 by morphological and molecular markers using Inter Simple Sequence Repeats (ISSR) markers, to use this information in soybean future breeding programs. Eleven ISSR primers were tested and six of them amplified clear and reproducible bands. A total of ISSR fragments were detected, of which (65.7%) were polymorphic. Based on morphological and molecular analysis the four cultivars Giza 21, Giza 22, Giza 111 and Crawford have low genetic diversity and clustered in one group. Only Toano cultivar was positioned in another group. Moreover, the line H 30 as a promising genotype was highly diverged from other genotypes. It seems to be using Toano and line H30 as distinct and exotic g...
We investigated phylogeography of Larix sukaczewii and Larix sibirica using nucleotide variation ... more We investigated phylogeography of Larix sukaczewii and Larix sibirica using nucleotide variation at three following nuclear gene regions: 5.8 S rDNA including two internal transcribed spacers (ITS), cinnamyl alcohol dehydrogenase (CAD), and phytochrome-O (PHYO). We also included sequences of the 4-coumarate: coenzyme A ligase (4CL) gene region obtained in our recent study. CAD and PHYO showed very low nucleotide variation, but ITS and 4CL had levels of variation similar to those reported for other conifers. Pleistocene refugia have been hypothesized to exist in the Southern Urals and South Central Siberia, where four out of nine of the investigated populations occur. We found moderate to high levels of population differentiation (F ST = 0.115 – 0.531) in some pairwise comparisons suggesting limited gene flow and independent evolution of some refugial populations. In L. sukaczewii, low levels of differentiation were found among populations from areas glaciated during the Pleistocene, indicating their recent origin. Our results also suggest these populations were created by migrants from multiple, genetically distinct refugia. Furthermore, some haplotypes observed in populations from previously glaciated areas were not found in putative refugial populations, suggesting these populations might have contributed little to the extant populations created after the Last Glacial Maximum. Some authors regard L. sukaczewii and L. sibirica as a single species, while others consider them as separate species. The observed conspicuous differences in haplotype composition and distribution between L. sukaczewii and L. sibirica, together with high values of F ST between populations of the two species, appear to support the latter classification.
Larch (Larix Mill.) is one of the most widely distributed tree genera in Eurasia. To determine po... more Larch (Larix Mill.) is one of the most widely distributed tree genera in Eurasia. To determine population structure and to verify classification of five species and three varieties of the Eurasian Larix species, we investigated levels and patterns of nucleotide variation of two nuclear gene regions: the 4-coumarate coenzyme A ligase (4CL) and the coumarate 3-hydroxylase (C3H). In the 4CL region nucleotide diversity at silent sites (πsil) varied between 0.0020 in L. gmelinii to 0.0116 in L. gmelinii var. japonica and in the C3H region between 0.0019 in L. kaempferi to 0.0066 in L. gmelinii var. japonica. In both gene regions statistically significant population differentiation (FST) was detected among adjacent refugial populations of some species suggesting limited gene flow and/or long time isolation of some refugial populations. On the other hand, populations of L. sukaczewii from northwestern Russia, which was glaciated 20,000 years ago showed no differentiation. This result is consistent with recent postglacial origin of these populations. Haplotype composition of some of the investigated Eurasian Larix species suggested that they are considerably diverged. Some haplotypes were unique to individual species. Our results indicate that more intensive sampling especially from known refugial regions is necessary for inferring correct classification of Eurasian Larix species and inferring their postglacial migration.
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Papers by Ismael Khatab