Plant Variety Journal - IP Australia

laid out as a randomised block design with one replicate vine
per variety per block.
Measurements Ampelographic data following the descriptors provided by
UPOV TG/50/8 Grapevine (Vitis L.) were recorded for vines
grown under vineyard conditions as well as for those grown
in the pot trial. Leaf measurements were recorded for vines
grown in the pot trial. Leaf lamina length (L1) was recorded
from the point at which the petiole attached to the mid-apex
of the leaf. Similar measurements were made between the
point at which the lamina attached to the apices of the other
lobes (L2, L3, R2 and R3). Leaf widths were also recorded
between the two proximal (R3 and L3) and the two distal (R2
and L2) lobes. Petiole length was also recorded. These
measurements were used to calculate a number of ratios.
RHS Chart - edition
Origin and Breeding
A series of controlled crosses was devised by CSIRO vine breeder Dr. A. J. Antcliff
(deceased) to re-combine the characteristics of American Vitis species for selection
under Australian conditions. The crosses, which involved many different species
combined either through inter- or intra-specific hybridisations, were conducted in
1967 at the University of Illinois by Dr. H. C. Barrett, who was an employee of
CSIRO and acted under the direction of Dr. Antcliff. ‘Merbein 6262’ was selected
from a cross made between V. cinerea 55 (female parent) x V. cinerea 194-1 (male
parent). The seeds from the crosses were introduced to Australia in 1967 and
germinated at CSIRO Plant Industry’s laboratories at Merbein in NW Victoria.
Emergent seedlings were rowed out in progeny groups in the experimental vineyard at
CSIRO Merbein in 1968 and trained to a single wire trellis. These seedlings have been
maintained using standard viticultural practices. The progeny from which ‘Merbein
6262’ was selected was screened for a range of essential and desirable rootstock
characteristics under the direction of Dr. Ernst Ruhl and Mr. Peter Clingeleffer,
former and current employees of CSIRO Plant Industry, respectively. Based on its
nursery and propagation characteristics, which were measured using dormant cuttings
taken from the original seedling, coupled with the mineral status of its shoot tissues
measured over several seasons, ‘Merbein 6262’ was multiplied via dormant cuttings in
1988. Rootlings, produced from dormant cuttings propagated under mist over bottom
heated beds, were grafted with V. vinifera cv. Shiraz scions for further screening as a
rootstock in a replicated trial conducted at CSIRO’s Koorlong property in NW
Victoria from 1989 until present. Under the supervision of Mr Peter Clingeleffer, vine
performance and winemaking data were collected and analysed for this trial from
1995 until 2003. These data, along with additional information concerning its
nematode and Phylloxera tolerance collected under the guidance of Dr Steve Sykes
(CSIRO Plant Industry) and Dr Kevin Powell (DPI Victoria), respectively, were used
to select ‘Merbein 6262’ as a potential new rootstock for the wine industry. ‘Merbein
6262’ was selected because of: its very high rate of propagation by rooting dormant
cuttings; its graft compatibility with a major wine grape variety, viz. V. vinifera cv.
Shiraz; its tolerance to both the Rutherglen and King Valley strains of Phylloxera; its
ability to withstand infestation by three biotypes of root-knot nematode, viz.
Meloidogyne incognita, M. javanica (a) and M. javanica (b); its ability to regulate
potassium uptake into Shiraz berries such that optimum levels were attained for
premium winemaking; its ability to impart an appropriate level of vigour in Shiraz
scions matched by yield and fruit quality which are reflected in juice and wine quality;
its ability to impart good oenological characteristics to Shiraz grapes such that wine
quality in terms of colour density, total anthocyanins and total phenolics exceeded
Page 479 of 550
Plant Varieties Journal Vol. 21 No.3