breeder profile

Experience ranging Photographs: Keith Hammett from the showbench to government research institutes provided Dahlia ‘Dark Tiger’ a solid background for an independent plant breeder Keith Hammett The art of plant breeding

g u ess horticulture is in m y b lo o d . immediately following the Second World War Although I had little contact with either, and at that time the society had in excess of Iboth my grandfathers were professional 2,000 members. Included were many skilled gardeners in England and my father and exhibitors who competed successfully at uncles maintained good gardens. One uncle national level with a range of flowers and always had a good display of dahlias, while vegetables. Included amongst them was another separated his flower and vegetable Pi Ensum, Britain’s most successful Dahlia gardens with a row of sweet peas. exhibitor and breeder. I was drawn to both plants and at the age Even in the 1950s, a teenager interested of fifteen, with the encouragement of my in horticulture was a novelty, and I received parents, joined the local Worcester Park much encouragement and mentoring, which Horticultural Society in Surrey. Recreational enabled me to compete successfully both at

Alan Bilham horticulture was very strong in the decades local and national level. This in turn added

256 December 2008 PlantsmanThe relevance to biology classes at school, and I bench an exhibitor must learn to recognise subjected to much more rigorous selection went on to study botany at the University of traits deemed desirable and at the same pressures. Southampton. time they will be subconsciously selecting Competitive flower showing did define Throughout my time at university I rem­ potential parents. my initial work with Dahlia. I have always ained active in recreational horticulture and In the short term, exhibitor breeders are been attracted to neat and tidy, rather than served on the committee of the National often very successful, however, there are big and blowsy, so I set myself the goal of Sweet Pea Society and qualified as a judge longer-term consequences. Hobbyists work producing a series of show-worthy Miniature with the National Dahlia Society. Although with very small gene pools and narrowly Decorative cultivars in a full range of already starting to breed both sweet peas defined objectives. Both of these quickly colours. I remembered one of my early and dahlias, I opted for plant pathology for reduce the genetic variability of the mentors saying to me that it was unwise to my PhD topic. Once qualified, I was recruited material being used. In some genera, this cross two cultivars from the same breeder. by the New Zealand Department of Scientific can lead to inbreeding depression. In the Consequently, I chose as parents cultivars and Industrial Research (DSIR), and came to Dahlia, the pursuit of form has been at the that had been bred in different countries. Auckland, New Zealand in 1967. While this was no guarantee of genetic Immediately, I broke in a small home distance, it served me well and I achieved garden and continued breeding sweet peas. my goal. Probably the most successful After six years, I was able to buy a 4ha individual cultivar globally was Dahlia property on which I built a house. This ‘Elizabeth Hammett’, which is still being greatly increased my scope to indulge in exhibited today. further breeding Leaving the show bench An aesthetic activity When I read a plant catalogue, I try to look I believe that when engaged in any activity, for things that are missing. When I started it is important to frequently question what breeding sweet peas I was aware that one is doing and why. Over time we should although the original wild Lathyrus odoratus develop and refine an overarching is bicoloured, the goal of breeders subse­ philosophy for our work. For me, breeding quently had been to produce self-coloured ornamental plants is an aesthetic activity blooms where the standard and wing petals comparable to painting a picture or Primula ‘Blue Mountain’ are the same colour. Bicoloured sweet peas composing a piece of music. In contrast, were seriously at risk of being lost. someone who breeds crop plants is more Fortunately, I had acquired a small akin to an engineer. ‘When I read a collection of ancestral cultivars, among However, in both cases, plant breeders plant catalogue, which were some distinct bicolours. It was are privileged to be using plants that have not difficult to create a new strain by evolved over millions of years and it is I try to look for things crossing the best modern cultivars of the important to remember that we have a day with some of the old bicolours. I realised special responsibility to pass on wild taxa that are missing’ from the outset that it would take several unsullied to future generations. generations to fully combine the bicolour expense of colour, especially in the UK. characteristic with sufficient other traits to Deficiencies of exhibition breeding While in Australasia, where blooms are make the cultivars show-worthy, but this did Any breeding programme must have a exhibited without foliage, no consideration not matter as I was now working in another clearly defined goal; simply sowing open- is given to leaves or the plant as a whole. cultural environment, where the show-bench pollinated seed and looking to see what In as much as the numbers of plants had little relevance. The bicolour sweet peas arises is not breeding. Coming from a grown of an exhibition cultivar are very low, and later refinements have been offered competitive flower show background, I performance parameters such as propagation variously as L. odoratus ‘Two Tone’, ‘Love initially set out to produce cultivars that ability, garden worthiness and tuber chara­ Match’, ‘Melody Bicolour’ and ‘Pathfinder’. were capable of winning on the show bench. cteristics also tend to be overlooked, and Currently exhibitors, rather than nurserymen, the overall result is the production of a An excursion into fruit produce most, if not all, new cultivars of series of developmental cul-de-sacs. In The success of kiwi fruit (Actinidia chinensis) exhibition plants. For an individual, this is a contrast, plants bred for larger scale as an export crop from New Zealand in the natural progression; to win on the show- mainstream commercial production are early 1980s meant that greater emphasis ➤

December 2008 257 breeder profile

Dahlia ‘Timothy Hammett’ An un-named black and white Dahlia Dahlia ‘New Horizon’ was given to research into possible new crops. between pure scientific research, which contrast between wing and standard colour, When the department I worked for was split seeks to expand knowledge, and practical as demonstrated in the recently released in two, I chose to become a new crop plant breeding which seeks to produce cultivar ‘Erewhon’. specialist rather than a plant pathologist. useful plants. However, by working in The pepino (Solanum muricatum) was parallel, we have been able to produce a Further questions identified as a plant that might be trans­ body of published scientific knowledge that Dianthus is another genus that has long formed into an internationally viable fruit has, at the same time, had considerable interested me. As part of our studies into crop. Stuart Dawes, who had assembled a practical use. yellow pigmentation we posed the question unique gene pool over a quarter of century, With any plant there is usually a holy of why there were yellow cultivars of was due to retire in two years. My director grail to be sought. In the case of the sweet D. caryophyllus, the carnation, but not of the time, Dr Rod Bieleski, had the wisdom pea it is to introduce yellow pigmentation. of D. plumarius, the pink. As with our to enable me to overlap with Stuart and to To this end, I amassed a large collection of Lathyrus studies, we undertook collabor­ expand his breeding work. Low yields, Lathyrus species, including all that were ative research with pigment chemist unpredictable off-flavours and a propensity reported to have yellow flowers. When Dr Ken Markham. This in turn led to for fruit to bruise limited the success of the L. belinensis was discovered and named we pigment studies in Clivia. few commercial cultivars. However, all the obtained seed. Despite the genus being With all my work I have attempted to desirable traits needed existed in the gene notorious for interspecific breeding barriers, amass as large a collection of taxa, both pool available to me. I dev­eloped a number using embryo rescue techniques we were wild and cultivated, as possible. This is of collaborative studies, the most valuable able to produce hybrids and to integrate something that is becoming increasingly proved to be with Prof. Brian Murray a genes from this species into L. odoratus for difficult to achieve with increasingly cytogeneticist at the University of Auckland. the first time. Although clear evidence of rampant parochialism and draconian We made considerable progress in develop­ yellow pigmentation has been elusive, some ing lines of bruise-resistant fruit and lines interesting hybrids, such as Lathyrus ‘Blue with reliably acceptable flavour. Unhappily, a Vein’, have resulted from this cross. major restructuring of government research After producing the first series of institutes took place at the time when I was bicoloured sweet peas, it occurred to me poised to bring these two lines together. All that they might be more pleasing if the work on new crops ceased and a number of wings were darker that the standard petal, valuable gene pools assembled at consid­ in effect a reverse bicolour. This was a far erable cost, over many years, were lost. greater challenge than rescuing original type bicolours, as there were no obvious Going independent parents. However, by careful observation After two years I chose to work as an and a stepwise approach over nearly independent plant breeder, and have been a quarter of a century I did produce fortunate to maintain my relationship with L. odoratus ‘Leading Light’, the first reverse Brian and a succession of his research bicolour. More recently, modifier genes from students. There is an inherent tension L. belinensis have enabled a much greater Lathyrus ‘Blue Vein’

258 December 2008 PlantsmanThe biosecurity barriers. I do not believe that black disc and white ray florets. anyone can claim to own plants or animals I also work collaboratively on other genera that have evolved over millions of years. such as Helianthus, Nemesia and Primula. Mankind has contributed nothing positive to With the latter I have raised a number of this process. I do, however, fervently believe laced polyanthus cultivars such as P. ‘Blue that we have the responsibility to act as Mountain’. However, with the intro­duction of custodians of biosecurity and that this is a student loan schemes, undue emphasis on global, not just a local responsibility. molecular biology and poor career prospects To this end, I brought together the largest in horticulture and biolog­ical science, it is and most diverse collection of Clivia in New getting increasingly difficult to recruit Zealand, which enabled a comprehensive students of a suitable calibre. cytogenetic study of the genus and the naming of a new species, C. robusta. I have Clivia ‘Sandra’ Commerce and fashion raised a number of interspecific hybrids, Philosophically, it has been a privilege to including yellow-flowered cultivars such as species have been crossed with it for the approach plant breeding as an artist / C. ‘Sandra’. first time since its genesis over two scientist and not simply as a generator of Increasingly, I think it important that centuries ago. Dahlia ‘Titoki Point’ and new product. I have managed to survive as horticulturists and plant breeders should D. ‘Home Run’ are examples of cultivars an independent plant breeder, largely see the plants with which they work, growing with D. australis genes. because I established an infrastructure in the habitats where they have evolved. Possibly most significant has been the while working as a full-time scientist. Visits to Mexico for Dahlia and to South raising of tree dahlias with a range of However, I seriously doubt whether a young Africa for Clivia were humbling and funda­ colours other than lavender and white. This person today would be able to contemplate mentally altered both my paradigms and the was only made possible by an understanding doing anything similar. direction of my breeding programmes. of the ploidy level of specificD. coccinea To disseminate cultivars internationally accessions in relation to the various species and to garner royalties takes an enormous Dahlias and chromosomes of tree dahlia. Tree dahlias with greatly amount of time and effort, which detracts My Dahlia species collection enabled a enhanced garden performance have been from the time available for breeding. Plant detailed cytogenetic study that resulted produced by the use of species other than Variety Rights, Plant Breeder’s Rights and in a greatly enhanced understanding of D. imperialis, the best-known tree dahlia. Plant Patents are a good idea, but only work the nature of polyploidy in the genus. The mauve-floweredD. ‘Timothy Hammett’ if a sound, long-lasting propagation and Knowing the chromosome number of (putatively D. tenuicaulis x (D. apiculata x marketing infrastructure can be established. individual cultivars and species variants has D. coccinea) and its yellow flowered offspring The breeder, most often, is the last person enabled their genes to be used. In addition D. ‘Conundrum’ are the first to have been to receive any reward for his or her efforts, to the genomes of D. coccinea and D. pinnata released, but others, in a range of colours, while hard-won commercial arrangements already present in the garden Dahlia, new are in the pipeline. can easily be overturned by corporate A concept conceived with one genus can machinations. be extrapolated to another. The notion of All too often, a one-off chance seedling reverse bicolour sweet peas led me to realise will do better commercially than the that Collerette dahlias were either self- product of a coherent long-term breeding coloured, or if there was a contrast, the ray programme. Ornamental plants are a florets were darker than the collar. Now, fashion industry and the ornamental after many years work, I have produced horticulture industry provides very little reverse Collerettes which have a collar input into research and development. Can darker than the ray florets. The first of you imagine the car industry relying on these were D. ‘Dark Tiger’ and D. ‘Pale Tiger’. weekend hobbyists for future developments? Where does one stop? The attractiveness Notwithstanding, I am a plant breeder by of finely divided foliage in species such as choice and give thanks that I have been able D. dissecta and D. apiculata led me to develop to indulge myself in this way the Mystic Series with divided foliage, albeit in this case also darkly pigmented. I am also Keith Ha m m e t t is a plant breeder based in Lathyrus ‘Erewhon’ trying to perfect a Dahlia cultivar with a New Zealand

December 2008 259