Three selected uncloned Pop 2, Pop 3, Pop 4 and two cloned cell lines Pop cl1A and Pop cl2B were derived from the original cell line established from Phthorimaea operculella (ORS-Pop-93). Three new non-selected cell lines ORS-Pop-94A, ORS-Pop-94B and ORS-Pop-95 were also established from embryos of the same insect. Differences in morphology, growth rate and polypeptide profile were determined between these cell lines. All the cell lines were susceptible to the Autographa californica nucleopolyhedrovirus (AcMNPV). The cloned cell lines produced higher levels of AcMNPV (TCID-50 and PIB) than the parental cells and at the same rate as the Sf9 reference cell line. Substantial amounts of viral DNA were synthesized in the clone Pop cl 2B after infection with the granulosis virus of the potato tuber moth P. operculella (PTMGV) and a complete multiplication was obtained in the ORS-Pop-95 cell line. The comparison between Pop cell lines which support limited or complete replication of certain baculoviruses can offer insights into some of the molecular barriers which restrict the host range of these viruses. These cell lines with variable susceptibility to baculoviruses could also be used for in vitro recombinations, increasing their virus host range to be used for the control of this pest.
Problem statement: Very little is known about the genetic diversity and morphological variability present in barley landrace in KSA, a country experiencing loss of biodiversity because of replacement of landraces with modern landraces. Approach: The molecular markers RAPD and ISSR were used as an efficient tools to estimate the intra-and inter-cultivar polymorphism among six barley KSA landraces collected from different geographical regions in order to assess the genetic relationships and develop cultivar-specific molecular fingerprints. The long term objective was to use these fingerprints to identify molecular markers that co-segregate and could be used in isolating gene(s) which controlling some important traits, thereafter could be used in breeding programs (marker assisted selection). Results: Out of 20 and 10 primers of RAPD and ISSR, respectively, a clear and reproducible band profile of 13 RAPD primers and 7 ISSR primers were obtained. In RAPD analyses, 61 out of 111 bands (54.6%) were polymorphic. The number of alleles ranged from 5-15 per primer, with an average of 8.54 per primer. In ISSR analyses, a total of 53 alleles were detected, among which 16 alleles (30.2%) were polymorphic. The number of alleles per primer ranged from 5-10 with an average of 7.57 alleles per ISSR primer. The mean Polymorphism Information Content (PIC) values were 0.45 and 0.37 for RAPD and ISSR markers, respectively. Conclusion: ISSR is better than RAPD to detect genetic diversity among the barley landraces. The RAPDs and ISSRs have confirmed each other and the ISSR results are more realistic comparing to RAPD results regarding to the geographical distribution of the six barley landraces. The outcome of this investigation can help strengthen the exiting pool of information on barley that may help assess national barley programs in KSA
A collection of ten cultivars of tomato grown in Egypt were screened with 20 simple sequence repeat (SSR) primers in order to determine genetic identities, genetic diversity and genetic relationships among these cultivars. On an average, 38 alleles were amplified using SSR primers with scorable fragment sizes ranging from approximately 75 to 275 bp. 23 alleles were polymorphic thus revealing 60.5% of polymorphism. The genetic similarity estimated according to SSR data was scaled between 17.6 and 93.2%, suggesting the potential of SSR markers in discriminating among plants of close or distant genetic backgrounds. Unweighted pair group method with arithmetic mean (UPGMA) clustering grouped the cultivars into two groups where the two Egyptian cultivars Edkawy and Giza 80 were clustered in different group. In addition, clustering was found consistent with the known information regarding growth habit. The genetic distance information obtained in this study might be useful to breeder for planning crosses among these cultivars.
This work was carried out in order to develop early flowering barley lines. These lines will be useful to producers by enabling multiple crops within a single season and increasing production. Transgenic barley plants containing the natural early flowering time AtCRY2 allele from the Cape Verde Island (Cvi) ecotype of Arabidopsis have been generated using biolistic transformation. Immature embryo derived calli of two commercially important barley cultivars (El-Dwaser and El-Taif), were transformed using a pCAMBIA-2300 plasmid harboring a genomic fragment containing the AtCRY2-Cvi allele. Transformation was performed utilizing 600 immature embryos for each cultivar. Stable transformation was confirmed in T 0 and T 1 plants by using genomic PCR, RT-PCR and western blot analysis with AtCRY2 specific primers and antibodies, respectively. The transformation efficiency was 5.6% and 3.4% for El-Dwaser and El-Taif cultivars, respectively. Seeds from several T 1 lines were germinated on kanamycin plates and the lines that contained a single locus were selected for further evaluation. The transformed barley plants showed the specific AtCRY2-Cvi flowering phenotype, i.e. early flowering and day length insensitivity, compared to the non transgenic plants. The time to flowering in transgenic T 1 plants was assessed and two lines exhibited flowering more than 25 days earlier than the parental cultivars under short day conditions.
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