Study On Germplasm Enhancement Of Parthenocissus Tricuspidata And P.quinquefolia

Parthenocissus is an excellent virescence and beautification climber for vertical plane, also an ideal plant for vegetation recovery of hungriness, lithoid mountain and ravage of highway and railway. P. tricuspidata and P. quinquefolia are the two species most widely cultivated in the world. P. tricuspidata has developed cupule and stronger adsorbability, but grows slower. P. quinquefolia has stronger resistance and grows faster, but its cupule is undeveloped, so the adsorbability is weaker. The utilization of the two species is mainly on natural germplasm and no any report on their breeding. The shortcomings existed in the two species have not been resolved till now. This paper reported the results of germplasm enhancement on P. tricuspidata and P. quinquefolia through inter-specific hybridization, tissue culture, protoplasts culture, induced mutagenesis by chemistry. 1. Study on Inter-specific hybridization between P. tricuspidata and P. quinquefolia (1) According to the study on florescence and pollination biology of P. tricuspidata and P. quinquefolia, It was suggested that the emasculation while making cross should be conducted on blooming day or 1d before blooming day and pollination should be done 1²d after blooming. (2) Pollens of the two species could germinate on the surface of themselfs and pollen tubes could grow into styles. The self-fruitful rations were 5.6% and 2.9% separately. (3) More than 20000 flowers were artificial fertilized in year 2002 and 2003, but no any frut obtained. Observational results indicated that most heterogenous pollens could not germinate on stigmas. Even if germinated, the pollen tubes showed some abnormity such as winding, tip inflation and bursting. 2 48h after pollination, pollen tube was not founded in the style of mother parents. It can be concluded the cross-incompatibility was taken placed on the surface of stigma. 2. Study on tissue culture of P. tricuspidata and P. quinquefolia (1)Callus could be induced from anthers, filaments, tendrils, immature embryos and endosperms of P. tricuspidata and P. quinquefolia which were cultured in improved Gamborg medium (B5) supplemented with 6-BA 2.0mg.L-1 (the following unit is the same)and 2,4-D0～4. The suitable concentration of 2,4 -D and the inducing frequency of callus for P. tricuspidata were: anthers with filaments₁ mg.L-1(62%),tendrils 4 (72%),immature embryos 4 (100%),endosperms 0.5 (18%);for P.quinquefolia were: anthers with filaments 0.5 (78%),anthers 0.5 and 4 (52%),tendrils 0 (98%), immature embryos 0.5 (48%),endosperms 0.5 (4%)。(2) With L16(44) orthogonale design,16 mediums supplemented with 6-BA,NAA ,lactalbumin hydropysate(LH) ,gibberellic acid(GA3) were tested for differentiation of callus. Embryoids occurred from immature embryos callus in three mediums and the embryogenic frequency were 33%, 33% and 13% separately. The three mediums were: â‘ base medium (improved B5 ); â‘¡base medium + 2mg.L-1 6-BA + 0.1 mg.L-1 NAA + 300 mg.L-1 LH; â‘¢base medium + 2mg.L-16-BA + 0.5 mg.L-1 NAA + 100 mg.L-1 LH + AC 5%. But only the embryoids differentiated from base medium developed into normal seedlings and the germination rate of embryoids was 53%. 3. Study on isolation and culture of protoplasts of P. tricuspidata and P. quenquefolia (1)The sterile caespitose sprouts and callus of P. tricuspidata and P. quenquefolia were used for isolating protoplasts with enzyme mixture contaninig cellulase R-10, pectolyase Y23 and mannital. Results showed that only cellulase R-10 had distinct influence on the isolation rate; the isolation rate was obvious different between explants, the highest one was from the leaf of P. quenquefolia, the lowest one from callus of immature embryo of P. tricuspidata; the suitable enzyme mixture for leaf of P. trcuspidata was 0.5% cellulase R-10, 0.3% pectolyase Y23 and 0.6M mannital, the suitable isolation time was 8h. (2) The isolated protoplasts were cultured on solid, liquid and solid-liquid medium, but only the protoplasts from endosperm callus of P. quenquefolia developed into new callus. The new callus were cultured on Ms and improved B5 medium supplemented with NAA, 6-BA, KT, ZT, 2,4-D, PEG and other growth regulators, but no plant regenerated from any of the differentiation mediums. 4. Study on induced colchiploid of P. tricuspidata and P. quinquefolia The embryoids of P. trcuspidata in different development stage and the caespitose sprouts of P. tricuspidata and P. quinquefolia were emerged into different concentrations of colchicines solutions for different time. Results showed that:(1) Colchicines restrained the growth of embryoids and caespitose sprouts, especially to roots. The germination of embryoids of P. tricuspidata was restrained obviously when treated with 0.05% of colchicines solution for 48h, and restrained completely with 0.1% for 96h. (2) About 3.3% of colchiploid was induced when treated embryoids of P. tricuspidata with 0.05% of colchicines solution for 48h, the multiploidy cells accounted for about 40%. The colchiploids could reach to 13.3% when treated caespitose sprouts of P. tricuspidata for 24h, and the multiploidy cells could account for 62.5% to 75%. It meant that it was better to treat caespitose sprouts than to treat embryoids of P. tricuspidata for inducing multiploid with colchicines. (3) All the colchiploids induced in the experiment were mix multiploids, the multiploidy cells accounted for 40% to 75%, but the percentage had a decrease tendency along with the agamic propagation. Aberrant polyploidy plants of P. tricuspidata with 4 and 5 splits leafs were induced. (4) The RAPD analyse showed that there was obvious genetic differentia between colchiploid group and contrast group. The differentia also existed among the clone population of colchiploid. It could be deduced that the colchiploid changed not only on multiploidy, but also on DNA level.