Artemisia herba-alba, called Shih is a medicinal herbal plant found in the wilds. The biodiversity of this plant is heavily subjected to loss because of heavy grazing, land cultivation and collection by people to be used in folk medicine. In the current study, two cryopreservation dependent techniques to conserve the shoot-tips of in vitro grown Shih were evaluated: encapsulation-dehydration and encapsulation-vitrification. Shoot-tips of Shih were encapsulated into sodium-alginate beads. In encapsulationdehydration, the effect of sucrose concentration (0.5, 0.75 or 1.0 M) and dehydration period (0, 2, 4 or 6 h) under sterile air-flow on survival and regrowth of encapsulated shoot tips were studied. Maximum survival (100%) and regrowth (27%) rates were obtained when encapsulated unfrozen Artemisia herba-alba shoot tips were pretreated with 0.5 M sucrose for 3 days without further air dehydration. After cryopreservation the highest survival (40%) and regrowth (6%) rates were achieved when Artemisia herba-alba shoot tips were pretreated with 1.0 M sucrose for 3 days without further air dehydration. Viability of Artemisia herba-alba shoot tips decreased with increased dehydration period. In encapsulation-vitrification, the effect of dehydration of encapsulated Artemisia herba-alba shoot tips with 100% PVS2 for various dehydration durations (10, 20, 30, 60 or 90 min) prior to freezing was studied. After cryopreservation the dehydration of encapsulated and vitrified shoot tips with 100% PVS2 for 30 min resulted in 68% survival and 12% regrowth rates. Further conservation techniques must be evaluated to increase both survival and regrowth percentages.

Sources of resistance to tomato-yellow-leaf-curl-virus (TYLCV) were investigated in 16 accessions of three Lycopersicon species and 55 commercial tomato hybrids and cultivars . All commercial hybrids and cultivars were highly susceptible . Accessions of L. hirsutum, Lm hirsutum f. glabaratum and L. pimpinellifolium showed a wide range of reactions . Those of L. peruvianum, LA 385 ofL. peruvianum f . humifusum exhibited very high levels of resistance indicating their potential use in local breeding programs . In contrast to earlier findings, back indexing showed that all symptomless genotypes in this investigation were carriers of the TYLCV.

Twenty five tomato cultivars and one accession of wild tomato were evaluated for their resistance to branched broomrape (Orobanche ramosa) infestation. Tomato cultivars were found different in their resistance to Orobanche based on different growth parameters. Total Orobanche number, haustoria development and number of emerged Orobanche shoots were all different between tomato cultivars. Differences in the growth and fruit yield among tomato cultivars were also found in response to Orobanche infestation. Ranking tomato cultivars for Orobanche resistance indicates the existence of different resistance mechanisms in these cultivars. Relatively high to moderate levels of resistance were obtained in Tiny Tim, Acora, Castler, Pomodora, Orient, Red Alert and the accession LA 1478 of L. pimpinellifolium. The cultivar Tiny Tim showed the highest level of resistance for all measured parameters and in all experiments.

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An experiment was carried out to study the effects of four pollination techniques; Bumblebees (Bombus terrerstris L.), plant growth bioregulator (PGB) (Parachlorophenoxy acetic acid), hand vibration, and control (natural pollination) on tomato (Lycopersicon esculentum Mill) production in greenhouses. Bumblebees showed no problem in visiting flowers at a temperature range of 17-42°C during the day and 2-14°C at night. Bumblebee pollinated plants produced a yield per plant which was significantly higher than plants treated with PGB, vibration and the control, respectively. Fruit set of tomato flowers over 10 clusters was 99.1, 96.7, 76.7, and 65.7% for bumblebee treatment, PGB application, vibration and the control, respectively. In the bumblebee pollinated flowers, the quality of fruits was superior. The fruits were hard, with more seeds, and had a high specific gravity and better appearance. The average fruit weight was 100.3, 80.5, 84.1, and 70.6 g for the bumblebee, PGB, vibration and the control, respectively. The PGB treatment produced bigger sized but puffy fruits (108.4 ml). While fruit size in the vibration treatment was the highest (126.8 ml), followed by the bumblebee and the control which were 99.3 and 98.5 ml, respectively. Fruit specific gravity in the bumblebee treatment was significantly higher than other treatments, with no significant differences between the PGB and the vibration treatments. The least dense fruits were in the control treatment. Regarding the firmness of fruits, the bumblebee treatment gave the hardest fruits, while the PGB and the vibration treatments were intermediate and the control was the least. Average seed number per fruit was 177.0, 86.5, 61.8, and 89.8 for bumblebee, vibration, PGB and the control, respectively.