Proceedings 33 rd PGRSA Annual Meeting 181 POSTHARVEST RIPENING OF ZIZIPHUS MAURITIANA FRUITS: EFFECT OF 1- METHYLCYCLOPROPENE N. Sankhla 1 , H. S. Gehlot, P. Agarwal, R. Choudhary and S. Joshi ABSTRACT Ziziphus spp. constitutes an important source of low cost, nutritive, fresh edible fruits in arid regions of India. Superior cultivars (Ziziphus mauritiana cv. Seb) produce big plum sized fruits which are highly prized for fresh consumption. However, fully ripe fruits often become brown, loose their firmness and organoleptic qualities. This study was initiated to monitor changes in certain chemical constituents and quality of fruits of cultivar ‘Seb’ following pretreatment with 1-methylcyclopropene (1-MCP). Treatment with 1-MCP considerably prevented the decrease in fruit firmness and vitamin C content. 1-MCP treated fruits remained much greener than the control as evidenced by their higher chlorophyll content and exhibited a much lower level of lipid peroxidation. These results indicate the potentials of 1-MCP in delaying fruit ripening and extending the shelf life of Ziziphus fruits. INTRODUCTION Fruits of some of the newly introduced cultivars of Ziziphus mauritiana Lam. (e.g., Seb, Gola, Mundia, etc.), locally known as ber (Fig. 1), have become very popular in the Thar desert region of India.They constitute an important source of locally grown, low cost, highly nutritious fresh edible fruits (Pareek, 2001). The big plum sized fruit of cv. Seb is popularly nicknamed as the apple of the desert. Due to poor harvesting techniques, including post harvest infrastructure and handling, heavy losses are incurred during fruit distribution and marketing. In this region, during the peak season for marketing, the temperatures often exceed 35°C. A high rate of respiration, enhanced ethylene production, fruit softening and pathogen susceptibility further add to the reduction in the quality and market value of fruits. Thus, studies on improving post harvest quality and shelf life of ber fruits have immense importance in management of ber cultivation in Indian desert. Fruits of ber are considered to have a climacteric type of fruit ripening (Abbas, 1997). It has been reported that ethephon, an ethylene generating compound, not only induces a nearly uniform fruit ripening, but also produces attractive, better quality fruits (Bal, 2001). Thus, it is conceivable that fruit ripening can be delayed or prevented by controlling ethylene production or ethylene perception. 1-MCP is a relatively newly introduced nontoxic compound which blocks ethylene binding at the receptor level (Sisler and Serek, 1997). By inhibiting ethylene perception, it prevents or delays ripening and extends the shelf life of several fruits and leafy vegetables (Blankenship and Dole, 2003). 1-MCP is also quite effective in enhancing vase life and prevention of ethyl-induced shattering of flowers (Sankhla et al., 2001). 1 Texas A & M Univ. Agric. Res. Center, Dallas, TX, 75252, USA*, and Botany Department, J. N. Vyas University, Jodhpur 342001, India