Bananas, Past, Present and Future”    Pat Heslop-Harrison 16 August 2021

Pat Heslop-Harrison is Professor of Genetics at the University of Leicester, an insti­tu­tion famous for its impact on med­ical and bio­lo­gical sci­ence through such world lead­ing research as the Human Geno pro­ject and the DNA struc­tures of animal and plant life.  Perhaps less well known is the research going on into the applic­a­tions of such sci­ence into  areas such as agri­cul­ture and food sus­tain­ab­il­ity, as we face up to cli­mate change.  Our speaker could have ensured our interest by choos­ing to focus on any one of a number of staple crops: wheat, maize, rice, pota­toes, len­tils, soya etc.  But it was to be the humble banana which was to be his choice of main dish on the menu.

Professor Harrison opened his talk by explain­ing the import­ance of the banana as a lead­ing diet­ary staple and con­trib­utor to world food supply.  Around 120 mil­lion tons are now pro­duced world-wide, with cul­tiv­a­tion mainly in trop­ical and frost-free coun­tries. But only around 15% of pro­duc­tion enters world mar­kets.  India and China are the largest pro­du­cers, all con­sumed domest­ic­ally.  Elsewhere, the main pro­du­cers are Latin America and the Caribbean Islands, export­ing to North America and Europe.  These mar­kets opened up in the late 19th Century with improve­ment to ship­ping, stor­age for con­trolled ripen­ing and onward logist­ics, the trade becom­ing dom­in­ated by the likes of Fyffes, Pratts, Dole and Chiquita, who have about 60% of the market.

 

Bananas are a valu­able source of Potassium, fibre and vit­am­ins B and C.   According to the Guinness Book of Records, they are now the most con­sumed fruit — not only by ath­letes want­ing an energy boost from their high car­bo­hydrate and sugar con­tent!  Although a fleshy elong­ated fruit -the banana is botan­ic­ally a berry pro­duced by herb­aceous plants (not trees) in the genius Musa.  Originating in SE Asia, they come in all sorts of shapes and sizes (and fruit col­ours) and can grow up to 16 feet.  Cultivation began around 6000 BC when the ori­ginal wild fruit had large black seeds and so was dif­fi­cult to eat.  Seedless vari­et­ies have been evolved over the cen­tur­ies.  In the Tropics, smal­ler, firmer, bana­nas used for cook­ing are called plantains. The famil­iar yellow dessert fruit we enjoy are typ­ic­ally from the Musa Acuminata ‘Cavendish’ vari­ety. This became pop­u­lar in the 1950s when the Gros Michel vari­ety became unvi­able due to Panama Disease.  These typ­ic­ally arrive in our shops via refri­ger­ated (13.5 %C) sea con­tain­ers with the on shore arti­fi­cial ripen­ing pro­cess con­trolled by ethyl­ene gas.  This enables demand and supply to be care­fully con­trolled, and waste min­im­ised, before dis­tri­bu­tion to retail­ers.

 

Our speaker, who shares research with uni­ver­sit­ies in China and France, moved on to give us a taste of the sci­ence behind the cul­tiv­a­tion of the valu­able crop.  There are over 2000 known vari­et­ies of banana. These have been stud­ied and recor­ded by their (mil­lions )  of cell, gene and chro­mo­some struc­tures to give ‘band­ing’ pat­terns.  (A sim­ilar approach is used in vac­cine research).  This allows sci­ent­ists to estab­lish which vari­ety is related to what and facil­it­ates the iden­ti­fic­a­tion of nutri­tional value, disease/virus/insect res­ist­ance and cli­mate hardi­ness. What fol­lowed was much above your blog writer’s head, but sens­ing that we might be enlightened by the delights of CZH2 pro­teins and single Nucleo Polymorhisms, Pat sug­ges­ted we might refer to the Banana Genome Hub on the web. (it’s worth a look!

 

Professor Harrison con­cluded his present­a­tion with a glimpse into the future. Food sus­tain­ab­il­ity and reli­ab­il­ity will con­tinue to be major con­cerns.  We are all aware of the effects of pop­u­la­tion growth, eco­nomic expan­sion and, increas­ingly cli­mate change: much of the world seems aflame, or suf­fer­ing from extreme storms and flood­ing. These events are clearly already having an effect on agri­cul­ture -animal and plant- and water sup­plies and levels.  And there are other threats: the pop­u­lar ‘Cavendish’ vari­ety is becom­ing affected by the Sigtoka virus and much research into hybrid­isa­tion and genetic engin­eer­ing will be required to combat it. The same threats apply to other crops and give rise to other chal­lenges such as fungi, bac­teria and weed reduc­tion.  Major pro­grammes already under way have allowed food reduc­tion to keep pace with pop­u­la­tion growth but sadly there has been polit­ical res­ist­ance to these devel­op­ments, not least in Europe.

As might be expec­ted, Pat’s talk stim­u­lated more ques­tions than time allowed.  These included:  Was the Potassium con­tent in bana­nas harm­ful? (No)  Why was the Cavendish vari­ety so pop­u­lar? (Reliability in cul­tiv­a­tion, ease of trans­port –but try others avail­able in ethnic shops)  What might be the effects of cli­mate change? (Could extend or reduce areas of pro­duc­tion). Do bana­nas help ripen toma­toes (yes, they give off ethyl­ene gas).  And what is the cor­rect way to peel a banana? (From the flower end towards the stalk).