الفهرس | Only 14 pages are availabe for public view |
Abstract Saccharum officinarum is one of the world’s most important crops and produces a sugar that is valuable all over the world besides it is used in also as paper manufacturing and foot industry. Sugarcane, is constrained severely can summarized based on several reports: (1) sugarcane normally propagates by its bud, with a low proliferation rate and the reproducing part (the bud) is also the economically used part of the sugarcane plant, which restricts the availability of sugarcane seeds needed for cultivation, (2) Easily infected by soil- borne pathogens such as bacterial ratoon stanting disease and virus diseases. Mosaic and streak disease, which cause heavy losses in yield, (3) Normal breeding of sugarcane is a real problem due to poor flowering and seed set. Indeed, most crop improvement programs for this species were confined to evaluation and selection of naturally occurring clonal variants. therefore, the aim of this study was to apply different techniques of plant biotechnology and biochemistry i.e. tissue culture, in vitro propagation, molecular markers, analysis of (chlorophylls, phenols, Indols, carbohydrates and flavonoids) as biochemical methods can also help in sugarcane breeding. The initial approach for in vitro propagation protocol of S. officinarum was based on apical meristem (explants). Numerous experiments were carried out to provide an effective, reliable and reproducible protocol for in vitro propagation of sugarcane. The MS medium containing 2mg/l Kin +0.25 mg/l NAA showed the highest multiplication rate, with value around seven shoots per explant and gave the maximum number of leaves and nods while longest shootlet (18.7 cm) was recorded with 0.25 mg/l NAA for G.2003/49 cultivar. A positive relationship was found between BAp+ NAA combinations and rate of shootlets multiplication. MS medium having 1mg/l BAp in combination with 0.25 mg/l NAA showed a high rate of shootlets multiplication (4.9) , maximum number of leaves and nods, However the longest shootlet (16.9 cm) was observed on 2mg/l Kin +0.25 mg/l NAA for G.T.54-C9 cultivar. A well- developed elongated shootlets about (4-5 cm in length )were excised from shoot clump and cultured on½ MS medium supplemented with 2mg/l IAA+ 1mg/l NAA in favor of root elongation (2.03 cm). MS half salts strength medium supplemented with 1mg/l NAA alone enhanced the rate of root development (7.66) of sugarcane G.2003/49 cultivar. The maximum number of roots formed per shoot (3.3) was recorded on ½ MS medium supplemented with 1mg/l IBA +1mg/l NAA. Half strength MS medium supplemented with 1mg/l IAA+0.5 mg/l NAA (4.60 cm) produced best results in term of longest root /shoot on sugarcane G.T.54-C9. The in vitro derived plants were better acclimatized under ex vitro condition when transferred on specially made plastic trays containing peat moss + sand+ perlite (1:1:1) at periodical intervals of taking special care not to damage the roots. About 80-90% of the regenerated plantlets could tolerate and survive under ex vitro environment or greenhouse conditions for the two sugarcane cultivars (G.2003/49 –G.T.54-C9) respectively. The molecular characterization of S. officinarum by ISSR- PCR at the DNA level showed 6 subcultures of tissue cultures compered to original materials. While, ISSR technique can be successfully applied to determine the genetic fidelity of sugarcane plants. Amplification products were separated by agarose- gel electrophoresis to reveal band polymorphism. Out of 3 specific primers screened. The most informative oligonucleotides bands for both two sugarcane cultivars were detected. Three primers didn’t detect any somaclonal variations and showed 100% monomorphic bands. Quantitative determination of chlorophyll, total carbohydrate, non-soluble carbohydrate, total Indols, total phenols and total flavonoids using spectrophotometer were detected in leaves of the two sugarcane cultivars (GT.54-C9 - G.2003/49) through different stages (open field, tissue culture plantlets and acclimatized plants). The amounts of chlorophyll, total carbohydrate, non-soluble carbohydrate, total indols, total phenols and total flavonoids in plantlets were higher than those in acclimated plants and mother plants, respectively. In this study, it was concluded that micropropagation is an effective method for sugarcane culturing; This requires hundred plantlets from single apical meristem with qualitative and quantitative traits like mother plant and more stability through molecular analysis between different subcultures. |