In little more than ten years a massive international breeding programme has produced sorghums that crop much

better under a range of local conditions, but yields are still ten times higher in some countries than others. An

extensive collection of germplasm, gathered from around the world and now readily available to breeders, offers

new and exciting opportunities for breeding cultivars which combine a number of desirable characters that are

not incorporated in any of the existing cultivars

House, L R

ICRISAT Open Access Repository

SORGHUM BREEDING AN INTERNATIONAL PROGRAMME OUTLINED Dr L. R. House,SADCCIICRISAT Sorghum-M~llet Improvement  Programme, PO Box 776. Bulai$dyo, Lrmbabwe In little more than ten years a massive international breeding programme has produced sorghums that crop much better under a range of local conditions, but yields are still ten times higher in some countries than others. An extensive collection of gerrnplasm, gathered from around the world and now readily available to breeders, offers new and exciting opportunities for breeding cultivars which combine a number of desirable characters that are not incorporated in any of the existing cultivars. World production of sorghum grain for 1981 was 72 million tonnes produced on 17.8 million hectares, averaging 1507 kgiha (3) (compared to 56.3 million tannes pro- duced on 51.0 million hectares at I103 k g h a  in 1969-71) (2) .  Yields of individual countries of the world where sorghum is important varied from 4025 k d h a  in the USA to 278 kgiha in Niger (see Table I ) ,  showing the very wide range of yields pro- duced at present. Under optimum growing conditions, sorghum is known to yield 121 or more grain per hectare on a field basis. , Sorghum (3. blcolor) is important in the \emi-arid tropics, where it is used for food, brewing, animal feed, construction mater~al and fuel. It is also cultivated in several temperate countries, both north dnd south of the equator, where it is used primarily for animal feed. Important food uses of sorghum include: leavened and unleavened hread; bread from alkali cooked gram; p r -  ridge; boiled grain; noodles; beverages; dnd snacks such as pop dnd sweet sorghum. Research on sorghum is undertaken locdllr hy almost ail counuies where n is cul- tivated, bur several intcrnarional dgencies also have important sorghum prugrammm. T h a r  include: International Crops Research Institute for the SemiArid Tropics ;ICRIS,A'T); Collaborative Research Sup- liistitut dc Rechercht.~ Agronomiques 'Troji~calcs ct dcs Cultures \ '~vr~eres  Table  1. Araa, yield e n d  product ion  of t h e  world's m a j o r  s o r g h u m  producing c o u n t r i e s  (FA0 Product ion  Year Book, '981) Area Y eid Producr~on 1000 ha kg ha 1000t L S A  5355 4025 22360 Argent,na 2100 3595 7550 C h ~ n a  3004 2500 7510 India 1600C 719 11500 Yemen A R  697 911 635 Australia 649 1679 1090 (IRAT), centred in France hut active In 1 Germplasm resources West Africa; and FAO. A number of p r i  Reaouricr ul. g r r ~ t l p l ~ \ m  prov~dc the i vate companies, particularly In the USA, essential h w s  lor crop Inlproverncnt pro. ; Australia, and Switzerland, also undertake grammca. ICRISA'I' Ihrr heen inv~red hy I research on an ~nternarional brsis. the Internaurin~l h i ~ r d  for Plani Genetic I Resources IIBP(iR) to lakc resp~lnrihllnv I A scientrrt evaluates IS 8706. an acrosion ~n for the sorghum collection. ivhich rwiv 1 the world sorghum c.ollectron. Tlie coll~crion ' dh,lut !t,0"0 accosions. I(:KISAT rncludes some 26000 accessrons : is conrinu~llv involved In cnllcctlng $111. 8 ghum III new :1rcas, especially in t \ l r~ca ,  ' and 11~1 vometiinrs tltoroughl!. re-ct~llciiud I in areas I'mm { v h ~ ~ h  partiil i l~rli  v r l u r h l ~  tradnlonal varieties hrvc some. A g11i1~1 ~ ; example w ~ s  the d~sct~vcry  ill' the /cra/er.i . , varietal uniup Irum ccntrrl crstcrn Sudan ~ n d  the ?iam'hella Region 01 Erhi~~pia .  tllgli yleiding varieties md hyhrlds, prarluiing ~ o o d  quality fciod In manv parts of the world, now have zcrazcra In [heir prrcntage A Sorghum Duscriptor L.isr has heen printed in urnlprratan w ~ t h  the IRI'GR. and ICRISAT is rccumulatlng d e \ c r ~ p t ~ v e  datd about caih ;iccrsaion lor sturagc in it\ cl)niputer. 1mport:lnr sollucrions arc jirtlwn and characrerisrd In t h e ~ r  cynins (11 origin - a \ ,  lor exampleI cnllertion\ made in Ethiopia and Carneroun. I(:RISA'I' is establishing a cold \tore lor the long-term preservelion of reed, to avoid the nerd lor repeatedly growing new hatcher 111 sced, and to reducc rhc rlsk of gcneuc drlft Subutanrial parts of' the c~illcc- tlon are kept in rhe USA National Seed R c p i ~ \ ~ t o r v ,  Filn Cullins, and at Purdue L nivervrv. 'Thc collection is used extcn. sivclv: lor example, 37440 samples ivcrc distr~buted round the world from ICRlStlT in 1983. Tropical rorghums generally flower very late and grow very tall ~f they are grown our of the tropics, in the longer summer davs ot temperate zones. A malor pnlgrumme to produce rhorter plants, insensit~ve lo dav. lengths, was ln~tiated iointly by the USDA and Texas A & M L'niver\itv in I%Z. This is hasicallv a backcrossmg programme where short early segregates arc idenufied in h e  F, population m the temperate zone of Texas, backcrossed to the tropical parent in a winter nursery situated III the Puerto Rico tropics, and the backcross progeny selfed in a second generation in Pueno Rico. Generally four backcrosses are made. This has heen m extremely valuable appruath contribuung many hreedrng lines A sorghum breeder lwkrng at the heads of female (rn h ~ s  leh hand1 and male lrr~ht hand) parents in a production field of Hageen Dura No. 1 .  This hybrrd sorghum war recently released in Sudan to most of the world's improvement pro- there were 50% increases in yields during grammes. One outstanding example is he 1970s (2) .  Hybrid sorghums were first SC108, a recovered zerazera type; selections lsed in Chna in the early 1960s and are have been released in a number of countries low widely grown. They are also used in and it is commonly used in crossing pro- iouth Africa, but developmrnts elsewhere grammes. Several seed companies and n Africa have hecn sporadic. The first hvh- ICRlSAT also now have similar program- id was released in Sudan in January, 1983 mes for converting sorghum. To supp)rt the production of hybrids Besides sharing germplasm accessiuns here has h e n  a tremendous investment in and converted lincs, there has k e n  extm- reeding elite parents with desirable grain sive sharing of breeding stocks. Organis- haracteristics and resistance traits. Most duonssuch as ICRISAT, FAO, Texas A & M rop breeding is concerned with characters University and Purdue University have arried tn the cell nucleus, but cystoplnsm arranged uniform international trtals for ~utside the nucleus plays an Important rt~le yield, food quality and resistance to insects n breeding sorghum. The firrt cytoplasmic and diseases. This rapid distriburlun uf nale-sterility system, involving var~et~es of germplasm and breeding lines is an Increas- nilo as seed parents (donating cytoplasm) ingly important aspect of the improvemen! .nd varieties of kafir as pollen parents of sorghum. donating the genome), is stable, and many allinator parents can be found that restore Development of hybrids nale-fertility in the hybrid. Fortunately, it The identification of cystoplasmic-genetic s easy to use the milc-kafu system in male sterility in sorghum, identified by leveloping hybrids. STEPHENS and HOLLAND (S) ,  paved the Other cyroplnsmic systems have bccn way for the use of F, hybrids on farms. The dentified a able to diversify the system Use of hybrids spread rapidly in the USA in md avoid any serious effccta on production the late 1950s and they were subsequently f some severe yield-limiting trait arose that laken up in Europe. There has also been a vas closely linked to the facton that control npid in- in the use of solghum hybrids nale-sterility. An A2 system has now been since rhc early 1960s in a number of ht in  levelopd in the USA. There ue other hericpcl  munuia - particularly Argentina, ystems (for example, Maldani and .Mexico ad B d .  ihianagaram in India), but it is difficult A hybrid prqlrrmme was staned m Indu ~mpossible) to locate the factors Io 1958 and hybrids w m  released in the nat ratore male.ferulrty, and u, the m d  1960s. lo both Argrnuna and 1n.m l i  these systems is l~mired YC"."p. .m ..rn r-....... Sorghum breeders have long used the tradi- tional methods of selecting new varieties, or parents of hybrids, from s~ngle, three-way, or double crosses. As sorghum has perfect (complete) !lowers, with both stamens and pistils, it is necessary in crossing to remove the anthers by hand before flowering. Important components of the genetli var. ~ c c  of a trait are often additive, so seleu In among the progeny from such ir0SSKS ntinues to be a useful brced~ng techni. IC. Backcrossing, employd to transfer sired rmts into elite varieties, has heen )st cxtcnsively used in recent years in the nversion programme and to develop ale.sterile seed parents for pmducing ,brids. If a hybrid lrom a cross to un .line is itself male sterile, the pollinatrir rent is said to bc 'non-rertoring'. By &On- ~uous backcrossing a new &line can he velopd and the pullinator parent (B-line) its 'mamtiner' ( AxB producer an AJine). Sorghum is primarily aelf-pollinating hut ere are several s~mplc reccsslve genes - ~rticularly those referred to by hrnders as rale sterilcs 3,7' and 'antherless' - lllet sult In male sterility when they arc xnorypous. Population hrrcd~ng was lirst :veluped in maize; it is pr~marilv based on oss pollination, bur the same prccedure In be used by rntn~ducinp male sieril~tv :ncs into sorphum pipulations. I'ripuia- 3n hreeding In sorghum war tkst uqed hv , 1. Wehster but is now part of the hrccd- 8 strategy of most large progrdmmes ( 4 ) .  is advisable first to ~dentify carefully the lrents that are to he included in a popula- on, wh~ch can range f n ~ m  very few (Icss ian ten) to several hundred. After intrtxlucing male ster~lity genes, %ds of the parents arc bulked and random ~atcd, usuilly for three generations dl  low :lection pressure, to hreak thc linkdgcr ol :nes on the same chrrrmusumc. Varilius reeding procedures can then be Iollowed, sually Jepnding on the nuii~bcrs of yen- ,ations that can he ohtaincd per \cur dnd ~e her~tability of relevant trait(s). All the procedures are forms ol recurrent :Icctiun in which each cycle involves valuation and selection as one phase, and :cornbinauun as the other phase, in the fcle. Doggett used a mars selection prouc urc where a cycle was c(~mpleted each meration, whereas at ICRISAT an S2 ~mily xlcction procedure ia used tha~ :quires four uasons - I .c . ,  two years per yclc. Frequently nnn.restorers and remr. rs uf cytoplasmic male sterility are kept In ifferent populations w that lines derived ,om the populnuons can be used as parent! f hybrids. The value of recurrent selection is to rovide constant recombinations of genes; :lection can then result in constant nprovements in the level of expression of .ait(s) with little or no loss, in h e  genetic ariation on which selection is dependent. Analysis of two populations at ICRISAT ~ d ~ u t e d  gains in yield of IE1% in the JSIR and 7-1496 in rhc USIB populations fret three cyda of recurrent selection. 'he US populatioas arose fmm the combi- atiun of several populations introduced Span 27,3.1984 1X A grri emasculatrng sorghum m a  cro$srng block in lharlanu Anthen arr rrrn(,vc,d bi, rmascu- Btron to enabie cross poilinatron to rake piace from the USA: the 'R' and 'R' rcfer to vlcld and resistance to pram mould and msnminers or restorers n: cvtoplasmic $[em borer. T h ~ s  pr(xedurc I r  grdduallv male steril~ty 'I, Y~elds In the thud and being useu at ICKlSAl a\ scrccllinp ieclr- fourth cycles were equal I r )  those o! the niqura pcrmrt hybrid contm!. with no loss In variabll~ry. Good plants are conunuall! selected from Producuon stability the population and advanced h!. tiadtt~onal Stabllrt! of vieid IS an Important concept. procedures :i.e.. pcd~pre: brecd~ng Such w ~ t h  tu8{i iomponents: 0 I an inhcrcnt genr Imes. aerit'ed lrom ICRIbA7 populauons uc smhillr~: and (II! resistance to \,arlous after ten pears. have sprrrd round the traits that I I ~ I I  vield, such as slresses world. and several have been released for caused b! msect. disease. wcrd and use b!. l a m e n  in different counrr~ea. enr~ronmenral facrora. Gencuc s t a h ~ l ~ r v  The population hreedlng procedure pro- determrned by testing in a widr varlet! o! vides a powerful means of simultaneousl!. locauons Fullowing p r e l i m ~ n a n  yield tncorpnunp,  several trails: for example. evaluadon ai one Iocnt~on suhscquent Charcoaistalk rot, seen here, a an rrnporfant vreld-lrrnrt~ng dfsease oisorghum 7hr stalk rot is caused by a iungus and rs pafl~cuiarly assoc~ared wtrh drought stress about the trme of  flowcnng. Ilona and final c\'nluatlon 1s at up to 111 dimeferent placm. B m d l n g  lur rcslstancc 111 rnwcl, rllwar weed and en\*lronmcn~ul s ~ r c u  varlcs In mmplcxify, hut the appnvch ha+ commo features. It is cssenual to havc a C O N U ~  screening p r ~ c e d u r c  and  hi\ should hc slmplc and cupahlc of e v a l u ~ t ~ n g  Iarpc n u m b c n  of hrredlnfi lines. It la nccersan to locale sources of resistancc. searchlnp first among the mnrc apronom~call\ c l ~ t e  breedlnp stocks. 11 may a l u ~  k ncccaaart ti, search the permplasm cullec~lon lor rcrlr. tancc, or lo  find grcalcr BcnctIC L11vcrs11\ for the trait. Sources ol rcslstallce In UII. selected ~ r a d ~ t ~ o n n l  \'ar ette\ car1 hc difficult to use bccausc of poor adaptauon, so an ell or^ 8s made 10 develop rcblstnncc In ugrw ~ ( I ~ I c Y I I ~  useful \parIctIes. At ICMSAT. the ahlllt\ to acrcen lor reslstancc traits and then to IncorpurnIt. them In agronorn~cally IJOIIJ I~nc\  la occup\.  ing a major part 01 the total research cf10rt. such work 1% oh\,~ouslv m u l t ~ d i r c ~ p l ~ n a r \  and ~nvulve\ H !cam apprl~acli Some of the Importunl irrlt! are l191rd In l'ilhli. 2 .  hut the\ arc n11t equally ~ m j x ~ r t a n t  cvcr\.  \vhcrr whcrr sorghunl I \  prowI1. sit hrecd. Inp strnteyle\ have 10 he u'orkcd ~rui  1\11 a rcplonnl has15 Teble 2.Objectiv.s in t h e  Improvement  of r o r g h u m  tor t h e  n m l r r i d  t r o p i c s  1 Good and s l a b l ~  vtsld i Habuonsc to l r r t ~ l ~ s a t ~ o r ~  loor <l ninri d(F!mentl 3 Abil~ty In conlributt'wller~ rilrl cropulny 4 At>il~!y ttr wtttistanrl weed t)ressitrr 5 lo l r ranct~  lo hrghlv acid stills b hus~stance to n~ozsttrrl urlll trnll>rro l U t E  SIrCSS 7 l r a ~ t s  corrcrrned t r l  stanfl estatllrstl rnent, I e erncr(cenccA trrrougn # I  coltl or hot s o l  crust, and screrilrn[t vgoilr 8 Cold tolerance, particularly nl flowerln(l 9 Appropr~ate photoper~od restJonbe 10 Hes~stancr to stemborers n~tdpe  shootfly head buus arirl lposs~hlyl armyworms 11 Reslstancr lo grain moulds stitti rots downy mildew a number of Ian1 d18easer. Smuts and vtruses 12 Hes~starlce to the parasltlc wrvtl Striqir 13 Good food quallty 

Sorghum breeding an International programme outlined

http://oar.icrisat.org/9015/1/SPAN_27_3_132-134_1984.pdf

Sorghum breeding an International programme outlined

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