Multiplication, Phenological Period and Growth Vigor of Thirty-One Grapevine Rootstocks and the Role of Parentage in Vigor Heredity

Knowledge about the growth vigor of grapevine rootstocks is required for scion-based rootstock selection and rootstock breeding. We performed this trial aiming to evaluate the multiplication and growth vigor of several rootstocks. Thirty-one rootstock genotypes were compared on their multiplication characteristics, phenological periods, and growth indicators across three consecutive seasons. The results suggested that the cuttings of most rootstocks had callus-forming indices (CFIs) over 0.5 except for '188-08' (0.28). The rooting rate of '420A' was 5%, while that of the rest of the rootstocks was greater than 48%. The internode lengths of the one-year-old vines were positively correlated with those (as well as cane lengths and pruning weights) of the adult vines. These rootstocks were grouped into three clusters based on the growth measurements across three seasons. Eight combinations of genetic backgrounds showed various effects on the growth indicators. The high-vigor cluster includes '1103P', '5BB', '225Ru', etc.; the medium-vigor cluster includes 'Dogridge', '101-14M', 'Fercal', etc.; and the low-vigor cluster includes 'Gloire', '3309C', 'Ganzin1', etc. The Vitis berlandieri parentage showed a higher vigor heredity, while the V. riparia showed a lower vigor heredity. These findings would contribute to rootstock nursery construction and provide references for vigor-based rootstock selection for grafts and parent selection for rootstock breeding.