Evaluation, identification and collection of better her (Zi~iphus spina-christi L.) varieties in Iran for breeding and quality and quantity development of them in arid and semi-arid zones

Inglés. Ber (Ziziphus spp.) is one of the tropical and subtropical fruit trees that belongs to the Rhamnaceae family. It is grown in Iran, India, Afghanistan, Bermeh, Syria. Lebanon, Palestine, Australia. America. Spain, Italy, France, and Southern Africa. Ber is well grown under the different climatic conditions, from the sea level up to 1000 m elevation. Ber is the hardiest cultivated fruit tree to drought and salinity and can play an important role in developing of arid region agriculture. Its deep taproot enables it to survive under extended moisture stress even when the surface soil completely dries out. Lower loss of water through leaf transpiration makes ber trees more adapted to arid microclimates. Ber grows well under varying climatic conditions. Commercial ber plantations are found growing in areas having a minimum temperature of 4 to 12 °C and occasionally reaching as low as -2 °C for short periods. Ber trees can withstand extremely high summer temperatures and are found to grow well in regions having maximum temperatures of 39 to 42 °C, and can tolerate temperatures as high as 49-50 °C. However, fruit set is adversely affected at temperatures above 35 °C. Natural groves of ber grow and produce well in subtropical and tropical regions receiving over 400 mm annual rainfall. Fruit yields are higher during higher rainfall years. Ber trees appear to tolerate roadside pollution because they maintain high chlorophyll content, particularly chlorophyll b, although their growth becomes retarded. Even after fire damage, most plants of ber sprouted within 3 months. The regrowth was mainly from new shoots that arose from just above or just below ground level in the case of young plants and from the buds in the canopy or epicormic buds on the stems of older plants. Since its cultivation requires little care, the fruit tree is suitable to rehabilitate extensive resource-poor areas: it also exists in wild groves, which are widespread in the warmer parts of India and in the northern parts of Australia. As well as the fruits, the wild trees also yield of marginal value, brushwood, fuelwood and leaf fodder. The tree propagates freely and greatly resists recurrent drought. It is thus an important tree suitable for integration into agroforestry systems of warm desert ecoregions. The tree can help in economic sustenance and insurance against ecological degradation. The central plateau of Iran is one of the most renowned drylands of the world. With a total land area of about 165 million hectares, the country is located in the south west of Asia and in the dry belt of the world. 80% of Iran's total land area has an arid or semi-arid climate and is thus vulnerable to desertification. The average annual rainfall in Iran's deserts is less than 50 mm and the country's average annual rainfall is approximately 230mm. Deserts and desertified lands account for 34 million hectares of Iran's total land area, out of which 12 million hectares are sandy or covered by shifting sand-dunes. Under such condition, ber can play an important rule in limiting desertification. In wild ber groves, there are some good varieties that can be used

Inglés. for commercial fruit production. The survey work was initiated in 2000 and over a three-year period more than 2500 Ziziphus trees have been studied and the ripe fruits from the 12 selected trees were collected in western arid and semi-arid regions of Iran (Khouzestan province). The survey was done by frequent, round-the-year visit to the different Ziziphus growing regions. The selection of the types was mainly based on i) plant characters, ii) time of fruit maturity and, iii) fruit quality and characters. The physical characters, such as fruit fresh weight, shape, color, length, diameter, volume, and drv weight, seed wet weight, drv weight, and shape, and •— ./ o cr. C1' r seedlessness were recorded. Information collected from the survey revealed that the Ziziphits trees differ widely in characters of average fruit fresh weight (2.4g-19g). fruit shape (olive form, ovate, oval, oblong or round), fruit color (bright brown, brown, yellow, reddish-brown or greenish-yellow), average fruit dry weight (.85g-4.7g), average fruit length (10 mm- 48 mm), average faiit diameter (12 mm-27.5 mm) and average fruit volume (2.2cc-20.2cc), seediness (seeded or seedless), seed shape (oval, ovate, oblong or round), seed wet weight (0- 1.3g), seed dry weight (0-0.76g) and seed volume (0-1.2g). The fruits were seedless in AT23, AT25, and AT29, but were seeded in other selected types. The maximum average fruit fresh weight was 19g in AT15 compared with 2.4g in AT23. The maximum average fruit length was 48mm in AT15 compared with 8mm in AT23. The maximum average fruit diameter was 27.5mm in AT15 compared with 10mm in AT23. The maximum average fruit volume was 20.2 cc in AT15 compared with 2.2 cc in AT23. Based on the different characters. 12 types (AT01, AT05, AT06, AT07,AT10, AT13, AT14, AT15, AT20, AT21.AT24, AT25) were finally selected for cultivation. Ber is propagated by grafting the scion buds of the desired cultivars onto rootstocks. Seedlings of ber have been used as rootstocks for its propagation. No graft incompatibility has been observed between the scions of the commercial ber cultivars and the rootstock seedlings of ber. The best time and method for ber budding have been not studied in Iran yet. This project has been carried out using of CRBD (Complete Randomized Block Design) with three factors including i) time of budding (Spring and Summer), ii) budding method (T, -. and ring) and iii) Scion (tree A, tree B and tree C). Easy and clear separation of the bark from the wood in both scion and the rootstock occurred in late spring and late summer in Ahwaz city, therefore budding was done on this two times. Results showed that the best time and method for ber budding in Khouzestan Province are late summer (with 80.2696 success) and -. method (with 86.15% success), respectively. For evaluating the adaptability of ber varieties in Khouzestan Province, 9 -*- budding propagated seedlings from each of new identified ber verities (AT01, AT11, AT13, AT14, AT15, AT25, and AT27) have been cultivated in the Date palm and Tropical fruits Research Institute of Iran using of RCBD (Randomized Complete Block Design) with three replications. Local wild her tree seeds have been used for root stock production. The success rate was very low for some varieties. Probably this low success was not just related to variety but may be to suddenly low temperatures occurred in late autumn in 2004, that killed most of the budded seedlings that have grown up to 25-30 cm. Many pests and diseases attack these trees as well as other plants. In order to identify ber pests and diseases, a research has been carried out in different areas of Khouzestan province during 2000-2002. Sampling was done by capturing directly, aspirator and sweeping net. Purification and identification of the fungal have been made after the formation of the fungal, colony and its sporoluation on WA, PDA and NA. For isolating of bacterial causal agents, the suspension of infected parts in distill water have cultured on NA. All materials collected after sorting and coding were studied taxonomically. Identification of pests and diseases were done with cooperation of Plant Pests and Diseases Research Institute of Iran. Important pests and diseases of ber trees in Khuzestan that have been identified are as follow: Pests: Lepidoptera order Coleoptera order 1) Euzophera sp. Near bigella (Pyralidae: Phyctidae) 2) Saturnia SP (Sturnidae) 3) Alcidodes cf. Willcoksipic (Curculionidae) 4)Phradonoma sp (dermestidae) 5) Trogoderma SP (Dermestidae) 6) Acadaleyrodes rachipora Singh (Aleyrodidiae) 1) A. citri Priesner and Hosny (Aleyrodidiae) %)Parlatoria crypta Mckenzie (diaspididae) Hymenoptera order 9) Megachila SP (Megachilidae) order 10) Carpomyia vesuiana A. Costa (Tephritidae) Homoptera order order 11) Eriophyes cernus Nal (Eriophydae) Diptera Acarina Diseases: According to the result, disease causal agents of leaf spot disease identified as phyllosticta ziziphi, the rust as Phakopsora zizyphi-vulgaris, fruit rot as Rhizopus spp., Rhizoctonia sp., Penicillium spp. and Aspergillus spp., the Blossom rot as Botrytis sp., the bacterial leaf blight as Pseudomonas sp. and Inonatus rickii also isolated from the trunk. Leaf spot distribution was more than the other fungal diseases. The rust only observed in Dezfool and Abadan. Symptoms as leaf calico and leaf mosaic also observed on the wild ber (Z.nmmularid) in Behbahan and Daniels Shoosh regions respectively.