Fruit properties and genetic diversity of five ber (Ziziphus mauritiana Lamk) cultivars.

The present study was conducted on five ber (Ziziphus mauritiana Lamk) cultivars (Komethry, Pakstany, Um-sulaem, Toffahy and Peyuan) grown in Saudi Arabia during 2005 and 2006 seasons. The aim of the present study was to investigate fruit properties (fruit weight, length, diameter, shape, specific gravity, seed weight, pulp percentage, total soluble solids (TSS), acidity percentage, TSS/acid, vitamin C content total, reducing and non-reducing sugars). Peyuan cv. had the heaviest fruit weight, fruit volume and reducing sugar content however, it was the lowest in pulp percentage and non-reducing sugars among the five cultivars in both seasons. Toffahy cv. had highest fruit diameter and seed weight while, had lowest TSS %, vitamin C and total sugars values. Um-sulaem cv. had highest acidity percentage and vitamin C content and lowest fruit weight, length and TSS/acid. On the other hand, Pakstany cv. had highest percentage of both pulp percentage, TSS, total and non-reducing sugars. Finally, Komethry had the longest fruit. The molecular characterization and fingerprint identification of the ber cultivars was conducted using the ISSR (Inter-Simple Sequence Repeats) technique. The ISSR technique was able to uniquely characterize and differentiate between the five ber genotypes. Moreover, the genetic similarity tree showed that the cultivar Um-slaem is genetically distant from the other four cultivars and the two cultivars Pakstany and Komethry were genetically identical.

Integrated crop management of the lesser date moth Batrachedra amydraula Meyr. (Lepidoptera: Cosmopteridae) infesting some date-palm varieties in Egypt.

The present study was conducted during the two subsequent seasons of 2001 and 2002 in El-Beheira Governorate, Egypt, to evaluate the efficiency of some agricultural practices on the incidence of the lesser date-moth, Batrachedra amydraula Meyr. (Lepidoptera: Cosmopteridae) on some date-palm varieties, i.e. Sammany, Hayany and Halawy. The studied agricultural practices, were: covering clusters of flowers with paper craft, covering date bunches with porous plastic cloth, thinning of bunches and/or diverging strands of bunches using special metal rings. The infestation percentages of the lesser date moth for each of the evaluated varieties indicated that Sammany had the lowest value (22.68) as compared with Hayany (37.42) and Halawy (53.16), successively. So, Sammany variety was more tolerable to the infestation than the other two varieties. In an attempt to explain such variations in the infestation by Batrachedra amydraula, determination of wax contents as well as the histological studies of the green fruits of each variety were conducted. Results revealed that tolerance of Sammany to the infestation was due to relatively higher wax content (0.420 g/10 fruits) than that of either Hayany (0.220 g/10 fruits) or Halawy (0.320/10 fruits), respectively. Moreover, the lowest infestation percentage in Sammany variety was attributed to the structure of the outer and inner layers of fruits tissues, which could be considered as natural barriers against the insect pest, causing a considerable reduction in its infestation. To know the effect of the studied agricultural practices on the quality of dates, the physical parameters of ripened fruits (length, diameter, thickness and weight), in addition to the chemical properties of the same fruits (P.H, T.S.S, T.S. and E.C.) were also determined. There is a correlation between the studied chemicals, morphological and histological characteristics of the fruits on one hand and the calculated infestation rates on the other one. The tested varieties showed that Sammany variety had the lowest value of T.S.S (20.40) in comparison to Halawy (30.2) and Hayany (35.6). Also, the estimated sugar values were 23.60, 28.10 and 30.40 for the Sammany, Halawy and Hayany, consecutively.