Professor Hubert Rees was a leading plant cyto-geneticist who served with distinction as a Lancaster pilot in the latter stages of the Second World War. At the end of his first tour of 30 operations he was awarded the DFC; he then volunteered for a second tour, and soon after beginning this his aircraft was critically damaged over Germany. He was able to retain sufficient control to allow the crew to bale out before him and, unusually, all survived. Following capture, he and his fellow officers were sent to Stalag Luft 1 on the Baltic coast, where they remained until liberated by the Russian advance in May 1945.

Rees was posted missing in November 1944, but it was not until two months later that his family received notification of his survival and internment, together with a laconic personal message from Rees that he was “playing quite a lot of bridge”. In transit to his PoW camp he was caught in a night-time RAF raid, and was again lucky to emerge unscathed — an ex- perience he described only as “unpleasant” in notes made at the time.

Professor Hubert (“Hugh”) Rees was born in 1923 and educated at Llandovery and Llanelli grammar schools. He left school to volunteer for the RAF and after training in UK and Canada joined 75 Squadron (RNZAF) in 1944 to pilot Lancaster bombers. On demobilisation in 1946 he married his childhood friend, Mavis Hill, and enrolled as a student at University College of Wales Aberysthwyth, graduating with a first class honours degree in agricultural botany in 1950.

He was encouraged by his tutor, Professor P. T. Thomas, to specialise in plant cyto-genetics, and spent a few months at the John Innes Horticultural Institute under the tutelage of C. D. Darlington before taking up an appointment as lecturer in cytology at the newly formed Department of Genetics at the University of Birmingham under Professor Kenneth Mather. Here he gained his PhD and successfully applied the techniques of quantitative genetic analysis to the genetic control of chromosome behaviour in plants, from which he later built his scientific reputation.

In 1958 he returned to Aberystwyth as senior lecturer in agricultural botany, being promoted to reader in 1966 and ultimately professor and head of department. He rapidly established an internationally acclaimed school of study into the genetic control of chromosome behaviour in plants, and on evolutionary changes in chromosome organisation with particular reference to plant-breeding. He co-authored two widely read textbooks, wrote numerous scientific papers and became a well-known figure in the Genetics Society, where he regularly presented his latest findings and ideas. He was elected a Fellow of the Royal Society in 1976.

Throughout his career he concentrated on the way in which the results of his research could be brought to bear on improving the consistent yield of food crops from diminishing resources to feed an ever-expanding world population. During his tenure at Aberystwyth he was at pains to strengthen the traditional links in research between the Department of Agricultural Botany and the Welsh Plant Breeding Station, and to foster collaborative research between them and the Department of Genetics at Birmingham University under Professor John Jinks — an arrangement that enhanced the international reputation of all three centres. An illustration of his singular leadership style was the initiation of each new intake of his students to the joys of the countryside, especially through the climbing of Cader Idris. Rees’s customary and colourful rendition of Lewis Carroll’s Jabberwocky at departmental Christmas parties will be long remembered by successive classes of students. Such activities also reflected his eclectic interests and voracious reading habit, extending beyond scientific matters in a wide range of English and Welsh literature.

Rees had an impressive intellect, and was an inspirational teacher who left his mark on all who came under his supervision. Many of his students would go on to high achievement in research and university posts, at home and abroad, and all would remain lifelong friends. In 1977 he taught at the Australian National University at Canberra, and in 1983 he was appointed Vice-Principal at Aberystwyth. Between 1987 and 1990 he served on Sectional Committee 11 (Genetics) of the Royal Society.

He served on a number of advisory groups and governing bodies, including those of the Welsh Plant Breeding Station (subsequently the Institute of Grassland and Environmental Research and now part of the Institute of Biological, Environmental and Rural Sciences) and the Plant Breeding Institute, Cambridge (subsequently part of the John Innes Centre). Through the British Council and the University of Malawi he was also active in promoting academic and technical interactions with the Bunda College of Agriculture, with lasting mutual benefits.

Throughout his career he spent several study tours abroad in a number of different countries either as a research fellow or as visiting professor.

He is survived by his wife, a son and two daughters. Another son predeceased him.

Professor Hubert Rees, DFC, FRS, scientist and bomber pilot, was born on October 2, 1923. He died on September 13, 2009, aged 85