The effect of gamma irradiation on enhancement of growth and seed yield of okra [Abelmoschus esculentus (L.) Monech] and associated molecular changes

A. Z. Hegazi¹* and N. Hamideldin²

¹Horticulture Research Institute, Agriculture Research Center, Giza, Egypt.

²Natural Product Department, National Center for Radiation Research and Technology, NCRRT. Atomic Energy Authority P. O. Box 29, Nasr City, Cairo, Egypt.

*Corresponding author. E-mail: amalhegazi2000@yahoo.com.

 Accepted 23 December, 2009

   Abstract

This investigation was carried out to study the effect of different gamma irradiation doses and water soaking on okra [Abelmoschus esculentus (L.) Moench- Malvaceae] seeds of two varieties (Sabahia and Balady). Both varieties showed similar trends in response to different treatments. Gamma irradiation at 400 Gy was superior for both varieties in growth criteria enhancement, photosynthetic pigment contents, seed yield and seed quality. The results also showed that 300 Gy had positive effects with respect to all studied growth parameters. Seeds irradiated with either 500 Gy or soaked in water (hydropriming) for 12 h before planting showed lower effects than other treatments but still greater than the control (direct dry seed sowing). Soaking in water or application of gamma irradiation induced changes in the number of protein bands in the two varieties, but high doses of gamma irradiation (400 and 500 Gy) caused highest changes. The variation in DNA profile in responses to gamma irradiation treatments was detected by RAPD-PCR technique. In variety Sabahia, the percentage of polymorphism was 47.37%, but in variety Balady it was 50%. The relatively high doses of gamma irradiation (400 and 500 Gy) induced more changes in genomic DNA pattern than the low dose (300 Gy).

Key words: Okra, gamma irradiation, hydropriming, protein patterns, RAPD-PCR.