I’m sure, like me, many scientists have a few publications that they treasure. No, I’m not referring to any which they themselves authored; rather, publications that made them sit up and pay attention, so to speak. And, in doing so, particularly stimulated their interest and perhaps even guided their own scientific careers subsequently.

I’ve now been retired for ten years, but I still look back to how I got started in the world of plant genetic resources fifty years ago, and some of the scientific publications that pointed me in that direction. Let me backup a little and explain how this came about.

In 1967, I was accepted on to a BSc degree course at the University of Southampton (on England’s south coast) to study environmental botany and geography. I’ve written elsewhere about the three very happy years I spent in Southampton until graduation in July 1970.

The core of my degree course, particularly in my third or senior year, was a two semester ecology module taught in the Botany department, and different aspects of physical geography (such as geomorphology, biogeography, and climatology) in the Geography department. But I also took several shorter elective modules in Botany, including plant speciation, plant breeding, and population genetics. This latter course was taught by one of the pioneers in this field, Vice Chancellor Professor Sir Kenneth Mather who came to Southampton from the University of Birmingham (where he had been head of the Department of Genetics). He claimed (probably with some justification) that he was the only teaching Vice Chancellor at that time in the UK.

We were a small group of only six or so ecology students, and this module was taught by quantitative ecologist Dr Joyce Lambert (who was also my personal tutor). All of us were required to submit an extended essay of 4-5000 words on an ‘ecological topic’ of our choice. It goes without saying that Joyce hinted she would prefer essays about her interest, namely the application of numerical methods to study vegetation landscapes.

I did not heed Joyce’s ‘advice’; I guess she was not best pleased. Instead, and with encouragement from genetics lecturer Dr Joe Smartt, I chose to explore the relationship between ecology, genetics, and taxonomy (the related fields of ecological genetics and experimental taxonomy) in an essay about the concept of ‘ecotypes’. Simply put, an ecotype is a distinct form or race of a plant occupying a particular habitat.

So that was my aim. What would be my entry point? And which literature would be most useful for my purpose?

From the 1920s onwards, several botanists (Göte Turesson in Sweden, JW Gregor in Scotland, and three staff at the Carnegie Institute of Washington in Stanford: geneticist Jens Clausen, physiologist William Hiesey, and taxonomist David Keck) had studied the variation of species (genetically, physiologically, and taxonomically) in relation to their environments, and the role of natural selection on plant adaptation. There was a wealth of literature to delve into. But where to begin?

I was fortunate that, just a few years earlier, Professor Jack Heslop-Harrison (then Mason Professor of Botany at the University of Birmingham) published an important review paper about what became for me a fascinating branch of botanical science, the study of variation within species in relation to environment.

Forty years of genecology, published in Advances in Ecological Research in 1964 (Vol. 2: 159-247) was, for me, one of those formative publications. Not only was the review thoroughly comprehensive in its coverage, but had the added quality of being extremely well written. It has stood the test of time. Yet, it would be interesting to bring it up to date, introducing all the latest evidence based on molecular biology and genomics.

When I contacted Heslop-Harrison’s son ‘Pat’ (who is Professor of Plant Cell Biology and Molecular Cytogenetics at the University of Leicester) to request a copy of his father’s paper (I’d ‘lost’ the copy I once had) he told me that he began writing a review 100 years of genecology, but had never completed it.

He did make this interesting comment: When I started on a ‘100 years’ update, I was taken that some parts [of ‘Forty years of genecology’] sounded remarkably old-fashioned, while other parts could fit unchanged in a strong grant application made today. But how the combination of molecular/marker studies and modelling has really allowed genecology to take its rightful place in biology.

Immersing myself in the various concepts of ‘ecotype’, ‘clines’, and ‘infraspecific variation’ among many others, Heslop-Harrison’s review not only provided me with the impetus to fulfil a pressing course assignment, but subconsciously perhaps helped me make some decisions about a future career. I guess this was the first time I became really enthusiastic about any botanical sub-discipline. Later on, when I began working in the area of conservation and use of plant genetic resources, the study of variation patterns and adaptation in crop species and their wild relatives became an important focus of what I set out to achieve. In fact, understanding the nature of crop plant variation—and how to use it—is one of the fundamental concepts underpinning the value of plant genetic resources.

No study of variation in plant species would be complete, even today I believe, without reference to the pioneering work of Clausen, Keck, and Hiesey in California over several decades from the 1930s. Their work had been highlighted, of course, in Heslop-Harrison’s review. I went back to their original papers*.

And what an eye-opener they were: a classic set of papers, published between 1934 and 1958, describing experimental studies on the nature of species that really caught my attention, and to which I still return from time to time.

While others, like Turesson and Gregor, had also studied plant variation experimentally, their work was not on the same scale that Clausen and his colleagues achieved across central California, from the coast to the high Sierra Nevada.

Working with a range of species, they collected samples from different populations of each across this Californian transect and, using a reciprocal transplant approach, grew samples at experimental gardens on the coast at Stanford and at different altitudes in the mountains, at Mather and Timberline. So, for example, samples collected from coastal sites were grown at the high altitude garden, and vice versa and all combinations in between. Even the same species looked different under different environments, in terms of plant stature or days to flowering, for example, being just two of the many traits they studied. They were interested if these traits would persist when grown in another environment. Here is an example from yarrow or Achillea.

They studied how well plants from one environment thrived in another, identifying the adaptations that enabled them to survive, and understanding both the genetic and physiological basis for adaptation, while recognising some of the variants taxonomically, if warranted. Many were simply locally-adapted populations, or ecotypes. Just a beautiful and competent piece of science.

Anyway, come the summer of 1970 and having just graduated, I still wasn’t sure what I’d be doing or where. I’d been accepted on to the MSc course on Conservation and Utilization of Plant Genetic Resources at the University of Birmingham to begin in September. But while I had a guaranteed place, there was no funding. And without a studentship there was no way I could support myself and pay tuition fees.

That all changed at the beginning of August or thereabouts. I had a phone call from Professor Jack Hawkes, who was Mason Professor of Botany (succeeding Heslop-Harrison) and the MSc course director, letting me know he’d found some funds to support my studies. It was wonderful news, and I immediately began to make plans to move to Birmingham in mid-September.

There was one important thing Jack asked me to do: purchase a copy of a book that had just been published, and try and work my way through it before I landed up in Birmingham.

This book, Genetic Resources in Plants – their Exploration and Conservation, was more than an eye opener as far as I was concerned. It was as if the scales fell from my eyes. What a revelation!

The book was dedicated to Nikolai Ivanovich Vavilov. Until then I’d never heard of this eminent Russian geneticist, the ‘Father of Plant Genetic Resources’, who subsequently became something of a scientific hero of mine.

Edited by wheat breeder Sir Otto Frankel and FAO scientist Dr Erna Bennett, both pioneers of the 1960s genetic resources movement, this book was essential reading for anyone entering the new field of conservation and use of plant genetic resources.

It emerged from a technical conference held at FAO headquarters in Rome on 18-26 September 1967, and comprised 44 chapters penned by many if not most of the leading lights then in genetic conservation and crop and forestry specialists from around the world. As Sir Otto wrote in the preface, the book attempts to define and develop the principles underlying the various stages of exploration, conservation and utilization. Its usefulness will depend on the degree to which it succeeds in illuminating practical problems, rather than offering prescriptions or instructions.

In the course of my own entry into the world of plant genetic resources, I came to meet and become friends with several of the contributors.

The six sections covered topics in: (1) Biological background (the nature of crop diversity, centers of origin, taxonomy); (2) Tactics of exploration and collection; (3) Examples of exploration (crops and forestry); (4) Evaluation and utilization; (5) Documentation, records and retrieval; and (6) Conservation.

It became something of a ‘bible’ for me, and even today, I dip into its many chapters to refresh some of my ideas. Yes, the world of conservation and use of plant genetic resources has moved on significantly since its publication 50 years ago. Just think of the remarkable advances in molecular biology and genomics that nowadays open up a whole new dimension to our understanding of variation among important crop species and their wild relatives. And the impressive progress in computing for both data analysis as well as data management for crop germplasm collections. Fifty years ago, many things that we consider routine today were then but a pipe dream, if they were even on someone’s intellectual horizon.

I really do believe that anyone contemplating a career in plant genetic conservation as I was, 50 years ago, would benefit from delving into Frankel and Bennett, not only to appreciate how the genetic resources movement started in the 1960s, but also just how we have come in the five decades since.

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*These are the papers from the California group of Clausen, Keck and Hiesey:

• Clausen J, DD Keck & WM Hiesey, 1934. Experimental taxonomy. Yearb. Carneg. Inst. 33, 173-177.
• Clausen J, DD Keck & WM Hiesey, 1939. The concept of species based on experiment. Amer. J. Bot. 26, 103-106.
• Clausen J, DD Keck & WM Hiesey, 1940. Experimental studies on the nature of species. I. Effect of varied environments on western North American plants. Publ. Carneg. Instn. No. 520.
• Clausen J, DD Keck & WM Hiesey, 1945. Experimental studies on the nature of species. II. Plant evolution through amphiploidy and autoploidy, with examples from the Madiinae. Publ. Carneg. Instn. No. 564.
• Clausen J, DD Keck, & WM Hiesey, 1948. Experimental studies on the nature of species. III. Environmental responses of climatic races of Achillea. Publ. Carneg. Instn. No. 581.
• Clausen J & WM Hiesey, 1958. Experimental studies on the nature of species. IV. Genetic structure of ecological races. Publ. Carneg. Instn. No. 615.

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