Synthetic Seed Preparation, Germination and Plantlet Regeneration of Litchi (Litchi chinensis Sonn.)

Litchi chinensis sonn.) ranks second after mango amongst the most important fruit crops cultivated worldwide. Litchi is a very valuable crop throughout the world because it is a table fruit and wines are also produced from it. The existing cultivars are highly polyploidy and heterozygous in nature. It is propagated through air layering and marcottage methods and storability is very low. Synthetic seeds can be stored for a long time and its genetic constitution could remain the same. For germplasm maintenance and clonal propagation, synthetic seeds can be used. Somatic embryogenesis has been reported from anther or embryogenic suspension culture in various species of litchi. Regeneration via organogenesis and somatic embryogenesis from zygotic embryos has also been reported in certain species. Developing a methodology for getting somatic embryogenesis with a high frequency from zygotic embryos which is available once in a year, would be particularly useful for genetic improvement of litchi. Cotyledonary stage somatic embryos developed from zygotic embryos were encapsulated in 2% alginate gel. The encapsulated somatic embryos (ESEs) germinated successfully on 0.7% agar medium containing 3% sucrose concentration in NN basal medium (half strength of major and minor salts) with 1 mg·l-1 of gibbrellic acid. Percentage germination and plantlet development for ESEs was higher than that of non encapsulated embryos (NSEs). In comparison to different hormones, gibberellic acid has a significant influence on the germination rate of ESEs after one week of dehydration was seen maximum at 9% sucrose and abscisic acid (1 mg·l-1) in half strength of major and minor salts in Nitsch and Nitsch medium resulting in extended storage up to 90 days without loss in germination potential and capability to regenerate into plantlets. Normally developed plantlets regenerated from ESEs were successfully adapted to soil to obtain a full grown plant.

REGULATION OF PHYTOHORMONS ON THE REGENERATION OF SHOOT-TIPS OF ANTIRRHINUM MAJUS INTO PLANTLET IN VITRO

Tissue culture of Antirrhium majus was experimented by using the tip of shoots as the explants, and comparing the effects of NAA, IAA and 2, 4-D on the formation of adventitious buds. The results indicated that the effect of NAA was the best for the formation of adventitious buds, 5.0, 7.0, 9.0, 11.0, 13.0 mg/L BA combinatcd with 0.1, 0.5, 1.0, 1.5, 2.0 mg/L NAA respectively. The results show that combinations of the concentrations of BA 7.0-9.0 mg/L and NAA 0.1-0.5 mg/L were advantageous to the regeneration of buds and NAA was very important for callus growth.

Effect of Gibberellin,Light and Genotype on Somatic Embryogenesis and Plantlet Regeneration of Peanut

[ Objective] Peanut in vitro regeneration system was optimized to provide technical support for its genetic transformation and mutagenesis. [ Method ] The effect of gibberellin, light and genotype on somatic embryogenesis and plantiet regeneration of peanut was studied using Guihua peanut cuhivar as materials, leallets as explants, MS ＋ 10 mg/L 2, 4-D as somatic embryo induction medium, and MS ＋3 mg/L 6-BA ＋0. 8 mg/L NAA ＋ （0 - 15 mg/L） GA3 as plantlet induction me- dium. [Result]The somatic embryo induction rate of five peanut varieties under light condition of light： dark = 14 h： 10 h was significantly higher compared with that under dark condition by 7, 5 - 37.5 percent points. Among different peanut varieties, Guihua 26 represented the highest somatic embryo induction rate of 62. 8%, while Guihua 833 represented the lowest somatic embryo induction rate of 21.7%. Adding 5 - 15 mg/LGA3 in plantlet induction medium was conducive to improving the induction rate of plandets derived from somatic embryos. With addition of 5 mg/L GA3, Guihua 26 and Guihna 771 represented the highest plantlet induction rate of 42.8% and 35.3%, respectively; with addition of 15 mg/L GA3, Guihua 836, Guihua 1026 and Guihna 833 represented the highest plantlet in- duction rate of 38.7%, 33.3% and 26.4L%, respectively. Among different combinations of peanut variety and GA3 concentration, plantlet induction rate reached the highest in the combination Guihua 26 ＋ 5 mg/L CA.3 arid reached the lowest in the combination Guihua 836 ＋ 15 mg/L GA3. [ Conclusion] Appropriate light conditions are conducive to peanut somatic embryogenesis in vitro. Adding GA3 in plantlet induction medium is conducive to promoting plantlet regeneration. Guihua 26 and Guihua 836 are the best peanut varieties among the experimental genotypes for somatic embryogenesis and plant regeneration.

Effect of desiccation on regeneration frequency of green plantlets and some biochemical properties of calli of wild rice

Wild rice is an important resource of usefulgenes to rice breeders. However, low regener-ation frequency is an obstacle to use the valu-able genes. We used desiccation to improve theregeneration frequency and studied the bio-chemical changes of calli of wild rice after des-iccation.Materials used in this experiment werewild species O. rufipogon, O. meyeriana, O.alta, and O. brachyantha. Young panicles(0.1-0. 5 cm in length of the inflorescence)

Effect of agar concentration in media on green plantlet regeneration frequency in rice anther culture

We studied the effect of agar concentration inmedia on callus induction rate and green plant-let regeneration frequency in rice.Materialswere Fgeneration of indica/indica or indica/japonica,which were 96E76(Hei’e/Zhaiye- qing 8),96E80[(IR 24/Guanglu＇ai 4//Zhongnan’ai)/Yifengzao],96E86(Zhong- munong 9/Zhaiyeqing 8).The induction mediaused was M8+2mg/L 2,4-D,and agar con-centrations were 0.6％,0.8％,and 1.0％,respectively.Regeneration media was MS+2mg/L KT+0.5mg/L IAA+0.5mg/LNAA,and agar concentrations were 0.6％ and1.0％.Results indicated that the calli induc-

Studies on the isolation and culture of protoplasts from Kappaphycus alvarezii

In this study, protoplasts were successfully isolated from Kappaphycus alvarezii using snail enzymes, abalone enzymes and cellulase. The optimum enzymic ratio was fixed to be 20% of abalone enzyme, 12% of cellulase and the osmotic stabilizer was 2.0 mol/L glucose. The optimum enzymic hydrolysis conditions were found to be dark enzymolysis at 30°C continuing for 4.0 h. The resultant density and yield of protoplasts achieved 32.60×10^4 mL-1, 65.20×10^4 g-1 tissue for Kappaphycus alvarezii. Finally, under the temperature of 20°C, light intensity of 1 500–2 000 lx and photoperiod of 12 h/d, two developmental pathways were investigated：（1） callus-like cell mass and regenerated plantlet occurred on protoplast;（2） young shoots and calluslike cell mass occurred in tissue blocks after enzymolysis.