استحداث التضاعف الكروموسومي و التقييم المبكر لشتلات الخروب Ceratonia siliqua L.

الملخص EN

This study was conducted at Forestry Department for the period 1st February until the end of November 2007 .

to achieve chromosomal polyploidy in Ceratonia siliqua L.

by soacking their seeds in different Colchicine solution concentration Zero .

500 .

1000 .

2000 ml / l .

and different periods 6 .

12 .

18 .

24 hr .

The treated seeds with different colchicine concentration mentioned above were Sown in plastic bag polly ethelen containing Sandy loam soil .

Other seed lots treated with colchicine were placed in incubator after sowing them in Petri – dishes to count seed germination percentages followed by chromosome counts in root apices as following : Colchicine concentration effect :The results showe a tetraploidy level 4n = 48 chromosome when seeds soacks in 2000 mlg / l concentration of colchicine solution pre – sowing with Ratio of 44.96 % .

but for 1000 mlg / l conc.

of colchicine the mean ratio of tetraploidy level was 20.21 % .

while tetraploidy was not noticed for other treatments which was diploid 2n=24 .

traits studied the 2000 mlg / l caused a significant increases 13.7 % for germination ratio .

40.96 % for Shoot length .

37.00 % for Shoot diameter .

and 51.85 % for Stomata length .

On the other hand this colchicine concentration causes significant decreases in the following traits value percentages 28.49 % for leaf shape factor.

and 46.53 % for Stomata numbers in 1mm2 in comparisons with soacking seed in water only without colchicine .

Soacking periods effects :The Soacking period of 24 hr.

was significantly increased for all traits studied except leaf shape factor .

and numbers of Stomata 15.66 and 13.30 % in comparison with shortest soacking period 6 hr.

.

Interaction effect of colchicine concentration & soacking Periods : Results Show that soacking seeds in colchicine solution 2000 mlg/l for 24 hr.

was highly significant and caused reduction in values of the following traits .

Leaf Shape factor 39.08 % and numbers of stomata / mm2 55.00 % .

at the same time this interaction gave significant effect in the following traits : germination ratio .

shoot hight .

shoot diameter .

stomata length and stomata width which they recorded values of 20.55 .

55.82 .

49.52 .

62.22 and 61.84 % respectively when compared with values of those seeds soaked in water only .