Study On The Characteristics Of The American Grape Varieties Conquister And Alachua

V. labruscan cv. Conquister and V. rotundifolia cv. Alachua are two varieties of grape introduced from American. Studies were carried out on the morphological, agronomic and fruit characteristics, as well as cutting propagation, hardiness and disease resistance of Conquister and Alachua. At the same time, the regenerating system of Alachua was studied. The results showed that:1. The color of Conquister's shoots tip mauve; the margin is light red with dense villus. The color of young leaves is glossy mauve. The shoot is semi-erect with medium silky villus and the internode is mauve. The mature shoot is filemote. The mature leaves are medium cordiform with deep green color. The profile is flat with silky villus on the back. 3 to 5 lobes; the upper sinuses are deep and open, with a U-shaped base. The leaf margin has rounded serrations. The petiole sinus is a wide arch with a V-shaped base and the tendril is discontinuous and bifurcate.The color of Alachua's shoot tip is yellow green; the margin is light red, without villus. The color of young leaves is glossy yellow green. The shoot is erect without villus and the internode is light green. The mature shoot is chocolate brown with spots. The mature leaves are extremely small in reniform with deep green color. The profile is flat without villus on the back. The leaf is entire without lobs. The leaf margin has pointed serration. The petiole sinus is a wide ellipse with a V-shaped base and the tendril is discontinuous and non-bifurcate.2. Conquister cuttings rooted easily by cutting propagation. The rooting rate was 92.0% by chimonophilous shoots and was 96.5% by vegetative shoots. Alachua cuttings rooted with difficultily by cutting propagation. The rooting rate was 2.3% by chimonophilous shoots and 43.1% by vegetative shoots.3. The aroma of Conquister was strong and complex. Clusters were tight in berry density, averaging 220.0g. Averaging size is 18.3cm, conical. Berries were medium sized, averaging 2.64g. The berries were round, blue-black and had bursas. The berry bloom was medium sized.The juice yield is 72.2%, and the color of the juice was light red. The soluble solid was 16.2%. Reducing sugar was 154g/L. Total acidity was 8.2g/L and tannin concentration was 2.00g/L. The berry had two to four seeds.4. Conquister had strong growth potential. The rate of budbreak was 95.2%. The rate of fruiting shoot was 96.5%. The rate of bunch/shoot was 2.8. It budded in the mid-March, and blossomed at the first of May. It ripened early (129 days from budbreak to ripeness). Alachua had weak growth potential. The rate of budbreak was 86.2%. The rate of fruiting shoot was 68.3%, and the rate of bunch/shoot was 1.1. It budded at the end of March, and blossomed at the end of May.5. The downy mildew resistance of Conquister was stronger than contrast grapes; Alachua was almost immune. Cold tolerance studies showed: Alachua had a sensitive area where leakage ratio of electrolyte increased sharply as temperatures decreased from -10℃to -15℃.The sensitive area of Conquister was from -25℃to -30℃.6. Establishment of regeneration system of Alachua was carried out using petioles as explants.The results showed that callus could be induced and the appropriate medium was B5+BA 2.0mg/L+2,4-D 0.5mg/L. The optimum medium for inducing adventitious buds was B5+TDZ4.0mg/L .The appropriate medium for rooting was WPM+IBA0.1mg/L.