Abstract
This paper reports the effect of different combinations of growth hormones on fresh and dry weights on callus cultures of two date palm (Phoenix dactylifera) cultivars Khalas and Sukary. MS-medium fortified with 2,4-D in combination with 2ip was the best for the production of callus fresh weight in cv. Khalas while MS-medium that contained NAA with 2ip was the best for callus growth in Sukary. In Khalas, MS-medium supplemented with 10mg/l NAA+ 1.5mg/l 2ip gave the highest(2.476gm) quantity of callus fresh weight compared with the other treatments while the lowest fresh weight was recorded in 15mg/l NAA + 0.5mg/l 2iP (1.17 gm) and 10 mg/l 2,4-D alone (1.28 gm). In Sukary, the MS-medium supplemented with 10mg/L2,4-D + 1mg/L 2ip gave the highest (1.6571g) callus fresh weight compared with all hormone treatments. However, this combination produced less callus fresh weight in cv. Khalas.
On the contrary, 10mg/LNAA + 1.5 mg/L 2ip gave the lowest fresh weight of 1.2088gm in Sukary, gave the highest callus fresh weight in Khalas. The callus dry weight followed a similar trend. In Khalas the media combination which gave the highest fresh weight, also produced the highest (0.1534 gm) dry weight. However, the cv Sukary responded differently and gave the highest callus dry weight of 0.2450 gm in media with 15 mg/L NAA + 0.5mg/L 2iP compared to cv Khalas which gave the lowest (0.0981gm) dry weigh under this combination. Correlation Coefficient also revealed genotypic differences both in callus fresh and dry weights. However, interactions were very weak in almost all the media combinations used.