Early growth and graft success in macadamia seedling and cutting rootstocks Mobashwer Alam1, John Wilkie2, Bruce Topp1 1Queensland
Alliance for Agriculture and Food Innovation, University of Queensland, MRF, Nambour, QLD. 2Queensland Department of Agriculture and Fisheries, BRF, Bundaberg, QLD.
Introduction
Results and Discussion
Low productivity is a significant issue in topical and subtropical trees like macadamia.
Cutting survival rate
Rootstock affects the productivity of the scion through water and nutrient translocation and exchanging information to the scion. Rootstocks may regulate the growth of the cultivars and transform the plant efficiency and productivity. The aims of the study are: To identify the variability of rootstocks on growth rate and graft compatibility
• The cutting survival rate varied from 0-100%. • Breeding line BHI2 had the highest survival rate of 100%, followed by ‘HAES842’ (91.7%) and M.jan3 (89%). • Among categories, high performing rootstocks (79%) showed highest striking rate and related genera had lowest (32%) • Wild Macadamia jansenii and high breeding value progenies of B1.2 generation had >60% survival rate.
To explore the relationships of growth parameters on the performance of scion.
• Breeding lines BHI-1 and BHI-2 produced strong cutting root systems and had better striking rates than existing rootstock cultivars.
To develop a rootstock selection tool to use in future macadamia improvement program.
Rootstock Growth Height increase rate relative to ‘H2’
Materials and Methods
Seedlings
Cuttings
150 100 50
BHY1 BHY2 BHY3 BHY4 BHY5
BHI1 BHI2 BHI3
M.tet1 M.tet2
M.ter1 M.ter2 M.ter3
HAES842 A16 A268 A4 D4 Daddow
High performing rootstock cultivars: H2 and Beaumont
M.jan1 M.jan2 M.jan3
Commercial cultivars: HAES842, A16, A268, A4,D4 and Daddow
BDW1 BDW2 BDW3 BDW4 BDW5
0
H2 Beaumont
Thirty three genotypes consisting of 5 hybrids of M. tetraphylla and M. integrifolia, 16 M.integrifolia, 2 M. tetraphylla, 3 M. jansenii, 4 M. ternifolia and 4 related genera were propagated as seedlings and cuttings in April-October 2014. Growth study was conducted on 29 genotypes representing seven different categories including-
Selected progenies from B 1.2 macadamia breeding program forStem diameter increase rate relative to ‘H2’
High yield efficiency (BHY)
Seedlings
Cuttings
150
High breeding value for yield (BHI)
100
Potential dwarves (BDW) Wild Macadamia jansenii (M.jan)
50
Wild Macadamia ternifolia (M. ter) and
HAES842 A16 A268 A4 D4 Daddow
BHY1 BHY2 BHY3 BHY4 BHY5
BHI1 BHI2 BHI3
M.tet1 M.tet2
M.ter1 M.ter2 M.ter3
M.jan1 M.jan2 M.jan3
Wild Macadamia tetraphylla (M.tet)
BDW1 BDW2 BDW3 BDW4 BDW5
H2 Beaumont
0
‘HAES741’ was grafted onto the rootstocks in July 2016.
Graft success • Graft success rate varied from 10% to 92%. • There was a positive correlation with final stem diameter and graft success. • In seedlings, BHI1 had highest graft success and BHI2 lowest. • Beaumont cuttings produced highest graft success followed by Daddow and BHI2 cuttings. • In both seedlings and cuttings, Macadamia jansenii and Macadamia ternifolia least graft success.
BDW1
H2
BHI2
Please contact Mobashwer Alam for further details on 0753811371 or
[email protected]
