A conservation strategy for New Zealand hop (Humulus lupulus)

Wiedow C1, Templeton K2, Pathirana R1 and Beatson RA2

  1. The New Zealand Institute for Plant and Food Research Limited, Private Bag 11 600, Palmerston North 4442, New Zealand.
  2. The New Zealand Institute for Plant and Food Research Limited, 55 Old Mill Road.

Hop (Humulus lupulus L.) genetic resources, the backbone of the NZ$27.4 million industry, is maintained in field collections in Nelson Province. None of the diseases or the insect pests, which have a significant impact on hops production in many parts of the world, has been reported in New Zealand. These diseases and pests could have a devastating impact on the New Zealand hop industry if there was an incursion in to the country, as was experienced in the kiwifruit industry during the Pseudomonas syringae pv. actinidiae outbreak in 2010. Considering the vulnerability of field collections, we have initiated long-term gene-banking strategies, including cryopreservation, to secure horticultural germplasm resources already in New Zealand. In this context, we have taken the first steps to ’back-up’ and conserve hop genetic resources as well. These comprise 95 accessions of European and North American origin which includes New Zealand-bred cultivars. To identify the accessions for ex situ conservation by cryopreservation, it is necessary to collate and analyse genotypic, phenotypic and geographic data using specialised software, which leads to defining the core collection. First results of genetic relationships (distance/similarity) in the hop germplasm using SSR showed that cultivars bred and developed in New Zealand are a mix of both North American & European H. lupulus gene pools. This insight into the diversity of the collection can help with breeding decisions, and more importantly will provide us with a core set covering the genetic diversity, for long-term conservation through cryopreservation.