Tendril quantity is positively correlated across nodes in an interspecific hybrid grapevine seedling population
Grapevine seedlings initiate tendril production at the transition point from spiral phyllotaxy to alternate phyllotaxy, usually a node in the range of the 4th node to 10th node. Nearly all grapevine species show intermittent distribution of determinant lateral meristems (the determinant lateral meristems being inflorescences or tendrils), in which two successive nodes bearing lateral meristems are followed by a node without a lateral meristem (the full expression of the lateral meristem patterning cycle is six nodes due to leaf alternation). However, some species and interspecific hybrids show other patterns of determinant lateral meristem distribution, including continuous distribution, in which no nodes lack lateral meristems, or other patterns. We examined seedlings in a population that segregates for tendril quantity. The population parentage is ((Vitis berlandieri × V. riparia) × V. biformis) × (V. labrusca × V. mustangensis). The presence or absence of tendrils for 18 successive nodes in the alternate phyllotaxy was recorded on 118 greenhouse grown seedlings. The first observation node was the first node in alternate phyllotaxy, which varies among the seedlings in the population. In 18 nodes, tendril quantity ranged from 12 to 18. Tendril quantity in lower nodes on a seedling is positively correlated with tendril quantity in higher nodes on that same seedling. When tendril quantities are compared between the three series of six nodes (nodes 1-6, nodes 7-12, nodes 13-18), all comparisons show significant positive correlation (p<01). In seedlings in which there is a change in tendril quantity across nodes, it is more common for tendril quantity to decrease at higher nodes than for tendril quantity to increase at higher nodes.
Hartman, L., Zhong, G.-Y. and Cousins, P. (2017). Tendril quantity is positively correlated across nodes in an interspecific hybrid grapevine seedling population. Acta Hortic. 1157, 137-142
Vitis, genetic, reproductive, quantity, pattern