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AGENCY FORWASHINGTON.^ INTERNATIONAL 0. C. 20523 DEVELOPMENT FRADUEOL BIBLIOGRAPHIC INPUT^ SHEET'
1. SUBJECT A.^ PRIMARY Agricul1ture^ AF00- CLASSI- (^) FB SECONDARY Plant production--Cereals--Sbrghum^ I
- TITLE AND SUBTITLE Purdue international sorghum^ program 3. AUTHOR(S) Axtell,J.D., 4. DOCUMENT 1972 DATE...^ IS.^ NUMBER 48p.^ OF^ PAGES^ 6.^ ARCARC^ **NUMBER
- REFERENCE** ORGANIZATION^ NAME^ AND ADDRESS Purdue 8.'SUPPLEMENTARY (Presented at NOTES AAAS^ (Sponsoring Washington^ Organlzatlon, meetingDec.,1^ Pub~lihers,^ Availability) 9 7 (^2) )
- ABSTRACT 10. CONTROL NUMBER^ 1.^ PRICEOFDOCUMENT PN-RAA-
- DESCRIPTORS sa13."PROJECT^ NUMBER
Nutritive value. Research^ -____."__ 14. CONTRACT NUMBER^ -___
Plant genetics^ ProteinsCSD-1175 Res. Sorghum .15.^ TYPE^ OF^ DOCUMENT AID 590-1.14-74)
PAPER, AAAS -WASHI NGTON MEETING 1. DECEMBER 26-31.- 197-
SUBJECTit \PURDUE INTERNATIONAL SORGHUM PROGRAM
A~OR JOH N Di AxTELL, .D.o DIRECTOR
INTERNATIONAL SORGHUM PROGRAM
ADDRES S': DEPARTMENT OF AGRONOMY
PURDUE UNIVERSITY
-PURDUE
WEST LAFAYETTE, INDIANA 47907
TIME: 9:00 Aim., DECEMBER 28, 1972
PLACE: WASHINGTON-HILTON HOTEL, GEORGETOWN EAST Room
PROGIRAM: AAAS^ Symposium#^ ORGANIZING^ FOR^ INTERNATIONAL
RESEARCH
.ADDRESS: ROGER SMITH HOTEL
NOT FOR PUBLICATION
2
RtLATIVELY HIGH PROPORTION OF THE TOTAL CEREAL ACREAGE PLANT- ED'TO SORGHUM AND MILLETS, ALMOST 25 PERCENT,^ AND^ (2)^ THE^ LOW YIELDS IN THESE AREAS, COMPARED WITH YIELDS IN THE^ DEVELOPED
COUNTRIES USING^ SORGHUMS^ AND^ MILLETS^ FOR^ STOCK^ FEED,^ THE^ FAR
EAST HAS THE GREATEST ACREAGE 1 i-.40.MILLION HA, WHILE AFRICA HAS THE GREATEST PROPORTION^ OF^ ITS^ TOTAL^ CEREALS^ AREA^ UNDER .SORGHUM AND MILLETS, ALMOST 60 PERCENT. THERE^ IS A^ GREAT NEED FOR INCREASED SORGHUM YIELDS^ IN^ THESE^ AREAS^ OF^ THE^ WORLD AND IT IS GRATIFYING TO^ NOTE^ THAT^ THIS^ NEED^ HAS^ BEEN^ RECOG- NIZED WITH THE ESTABLISHMENT OF I C R. I S A T AN^ INTERNA- TIONAL CENTER FOR RESEARCH IN^ THE^ SEMI-ARID^ TROPICS,^ DURING THIS PAST YEAR. THERE IS ALSO AN URGENT NEED FOR IMPIOVING THE NUTRITIONAL QUALITY OF THE GRAIN SORGHUMS^ WHICH^ ARE^ USED^ IN THE HUMAN DIET IN THESE AREAS OF^ THE^ WORLD.^ THIS^ NEED^ WAS RECOGNIZED IN 1966 BY THE U.S. AGENCY FOR^ INTERNATIONAL^ DE- VELOPMENT WITHTHE ESTABLISHMENT OF^ OUR^ PROGRAM^ AT^ PURDUE UNIVERSITY: WITH THE PRIMARY PURPOSE OF^ DEVELOPING^ AND^ RELEAS- ING SORGHUM GERMPLASM WITH HIGHER^ PROTEIN^ CONTENT,^ IMPROVED AMINOACID BALANCED AND^ BETTER^ TOTAL^ DIGESTIBILITY^ FOR^ UTI- LIZATION IN THE LESSER DEVELOPED COUNTRIES OF^ THE^ WORLD.^ OUR PROJECT (^) HAS MAJOR OBJECTIVES (^) IN THREE AREAS) RESEARCH, APPLI-, CATION AND UTILIZATION.OF THE^ RESEARCH^ FINDINGS,^ AND^ TRAINING. I WOULD LIKE TO DISCUSS EACH^ OF^ THESE^ AREAS^ TO^ ILLUSTRATE THE INTERDEPENDENCE OF^ THESE^ FUNCTIONS^ IN^ MEETING^ THE^ OVER- ALL 'OBJECTIVES OF ,THE,PROJECT, I SHOULD MENTION AT THE OUTSET
THATTHIS. PROJECT^ AT^ PURDUE-^ IS^ BOTH^ INTERDEPARTMENTAL^ AND
IN'TERDISCIPLINARYt I'NVOLVING^ -THEI^ DEPARTMENTS^ OF^ BIOCHEMISTRY.
ANM"AL.SC ENCE^ AND^ AGRONOMY^ WITH^ PARTICIPANT^ :*SCIENTISTS^ IN
THE AREA^ OF^ PROTEIN^ BIOCHEMISTRY,^ HUMAN:ANDANIMAL^ NUTRITlION# AS: WELL AS GENETICISTS,:,: PLANT^ BREEDRS,^ AND^ STATSTICINS
GRAIN.. PROTEIN: AVAILABILITY: IS: APPARENTLY LIMITED IN SOME
SORGHUM GENOTYPES BY THE PRESENCE OF UNIDENTIFIED POLYPHENO-
LIC COMPOUNDS LOCATirmAT"HE'TESTALAYER OF.THE GRAIN. THESL PIGMENTED COMPOUNDS (^) HAVE NOT BEEN WELL (^) CHARACTERIZED CHEMI- CALLY AND ARE*REFERRED TO GENERICALLY AS "TANNINS," THE TESTA LAYER LIES BETWEEN THE ALEURONE^ CELLS^ WHICH^ COMPRISE THE OUTER LAYER OF THE ENDOSPERM AND THE^ PERICARP^ OR^ SEED^ COAT AS ILLUSTRATED ON THE NEXT SLIDE, WE DO NOT FULLY UNDERSTAND HOW THESE TANNIN COMPOUNDS (^) INFLUENCE THE NUTRITIONAL (^) QUALITY OF SORGHUM, OUR HYPOTHESIS AT PRESENT IS THAT THE SEED PRO- TEINS BECOME COMPLEXED OR BOUND WITH THE^ TANNIN^ COMPOUNDS^ OF THE WHOLE GRAIN, AND THAT^ THE^ COMPLEXED^ PROTEINS^ ARE^ SUBSTAN- TIALLY LESS AVAILABLE FOR UTILIZATION BY MONOGASTRIC ANIMALS.
:AMINo AcID^ '^ COMPOSITION^ THE-AVERAGE^ PROTEIN^ AND^ AMINO^ ACID COMPOSITION OF^^522 LINES^ FROM^ THE WORLD SORGHUM COLLECTION IS PRE- SENTED IN^ TABLE^ 3.^ THE^ AVERAGE^ PROTEIN^ CONTENT^ OF^ THESE LINES IS 12.6 PERCENT AND THE AVERAGE LYSINE CONTENT (EX- PRESSED AS A PERCENT OF PROTEIN) IS 2,1 PERCENT.^ A^ MORE MEANINGFUL ASSESSMENT OF AMINO ACID CONTENT FROM A^ NUTRITION- AL POINT OF VIEW IS A COMPARISONOF, ESSENTIAL^ AMINO^ ACID^ CON- TENT IN SORGHUM WITH THE RAT REQUIREMENT, AS SHOWN IN FIGURE
3. THISILLUSTRATES THE^ DEFICIENCY^ IN^ LYSINE,^ AND^ THE^ EX- CESSIVE LEUCINE CONTENI' PRESENT IN SORGHUM, THE METHIONONE CONTENT OF SORGHUM IS-LOW, BUT IF ONE CONSIDERS THE CYSTINE,
6
CONTENfT OF 1.5 PERCENT (^) THE OVERALL SULFUR AMINO ACID (^) CONENT APPROACHES THAT REQUIRED (^) BY THE RAT$ THE TRYPTOPHAN (^) CQNTENT OF SORGHUM BASED (^) ON OUR EVIDENCE AT THIS TIME (^) SEEMS TO BE ADEQUATE WHICH IS (^) IN CONTRAST-TO THE LOW TRYPTOPHAN (^) CONTENT IN NORMAL (^) CORN.
FRACTIONATION OF WHOLE 5RAIN AND ENDOSPERM (^) PROTEINs. (^) DR. JAMBUNATHAN (^) AND (^) DR. MERTZ (^) AT PURDUE HAVE RECENTLY (^) COMPLETED THE FRACTIONATION OF SORGHUM (^) PROTEINS USING THE PROCEDURE (^) OF LANDRY AND MOREAUX (1970). (^) THIS PRO- CEDURE SOLUBILIZES (^) MOST OF THE NITROGEN OF SORGHUM (^) AND YIELDS FIVE DIFFERENT (^) SOLUBILITY FRACTIONS, RESULTS (^) OF THE FRACTION- ATI ON OF WHOLE (^) GRAIN FROM TWO LOW TANNIN AND (^) TWO HIGH TANNIN -SORGHUM LINES ARE SHOWN IN TABLE (^) 4. THE AVERAGE PERCENT NITROGEN (^) IN EACH FRACTION FOR THE LOW (^) AND HIGH TANNIN LINES IS.SHOWN (^) IN EACH COLUMN, WITH THE (^) AVERAGE LYSINE CONTENT EX- PRESSED (^) AS PERCENT OF PROTEIN FOR EACH (^) FRACTION IN PARENTHESES. A NUMBER OF OBSERVATIONS (^) COULD BE MADE BUT I WOULD (^) LIKE TO CALL YOUR ATTENTION (^) TO TWO, FIRST, THE DISTRIBUTION (^) OF PRO- TEIN, IN VARIOUS FRACTIONS (^) IS DISTINCTLY DIFFERENT BETWEEN (^) THE HIGH (^) TANNIN AND LOW TANNIN LINES. THIS SUGGESTS THAT THE PRESENCE OF-TANNINS HAS ALTERED (^) THE SOLUBILITY OF SORGHUM PROTEINS, (^) PERHAPS"BY BINDING OR FORMING COMPLEXES (^) WITH THE PROTEIN, THIS IDEA IS SUPPORTED (^) BY THE OBSERVATION. THAT THE FIRST FRACTION IN :THE HIGH TANNIN (^) SAMPLES IS VERY:LOW IN
WITH LYSINE, VITAMINS, AND MINERALS WAS SUBSTANTIALLY GREATER
THAN GROWTH ON 'THE RATION sUPPLEMENTEb ONLY WiTH VITAMINS AND
'MINERALS, IN CONTRAST; RATS FED THE HIGH TANNIN SORGHUM
.(IS6992) LOST (^) WEIGHT ON THE UNSUPPLEMENTED (^) RATION (^) AND GAINED
ONLY SLIGHTLY ON THE RATION SUPPLEMENTED WITH LYSINE, THIS
OBSERVATION WAS FIRST NOTED BY DR, MERTZ AND JAMBUNATHAN'ABOUT
AYtAR AGO USING OTHER HIGH.TANNIN SORGHUMS, AND HAS SINCE
BEEN REPEATED WITH SEVERAL HIGH TANNIN LINES, THESE RESULTS
SUGGEST THAT LYSINE'IS THE FIRST LIMITING AMINO ACID IN LOW
TANNIN SORGHUM LINES BUT THAT OTHER FACTORS ARE FIRST LIMIT-
ING IN HIGH TANNIN LINES,
THE RESULTS OBTAINED FROM LYSINE SUPPLEMENTATION EX-
PERIMENTS ARE SUBSTANTIATED BY DATA-FROM RAT, GROWTH TRIALS
CONDUCTE6 BY DALLAS OSWALT At PURDUE. IN THIS EXPERIMENT
WE USED17 LOW TANNIN SORGHUM LINES'AND 10 HIGH TANNIN LINES
WHICH REPRESENTED THE RANGE IN VARIATION FOR PROTEIN AND LY-
SINE CONTENT OF SORGHUM LINES AVAILABLE FROM OUR SCREENING
PROGRAM OF THE WORLD SORGHUM COLLECTION, THE RESULTS OF THIS
EXPERIMENT# ILLUSTRATED IN FIGURE 6, DEMONSTRATE THAT RAT
WEIGHT GAIN IS DEPENDENT ON LYSINE CONTENT IN THE LOW TANNIN
SORGHUM GROUPo BUT NOT IN THE HIGH TANNIN SORGHUM GROUP. THE
RERESSION OF RAT WEIGHT GAIN ON LYSINE CONTENT FOR THE HIGH
TANNIN GROUP IS NEARLY ZERO WHEREAS THE REGRESSION COEFFICIENT
FOR- THE LOW TANNIN GROUP IS ABOUT (^) 65. (COMMENT, I WISHI
HAD TIME TO COMMENT FROM THE HISTORICAL POINT OF VIEW ON THE
DIFFICULTI ES CAUSED BYTHIS DIFFERENCE IN RESPONSE TO" LYS INE'.
9
CONTENT BETWEEN HIGH^ AND^ LOW^ TANNIN^ SORGHUM^ LINES^ BEFORE^ WE
WERE ABLE TO DISTINGUISH DIFFERENCES BETWEENTHESE^ TWO^ GROUPs.
PERHAPS YOU CAN IMAGINE THE PROBLEMS WHICH WOULD^ BE^ INVOLVED
IN INTERPRETING THIS DATA^ IF^ ALL^ THE^ POINTSON^ THIS^ GRAPH
WERE INDISTINGUISHABLE, ONE WOULD CERTAINLY^ BE^ TEMPTED^ TO
CONCLUDE THAT CHEMICAL ANALYSIS^ FOR^ LYSINE^ CONTENT^ WAS^ UNRE-
LATED TO THE BIOLOGICAL VALUE OF^ THE^ GRAIN.)^ 'WE^ NOW^ HAVE^ A
SIMPLE, RAPID CHEMICAL ASSAY^ FOR^ TANNIN^ CONTENT^ WHICH^ SO^ FAR
HAS BEEN THOROUGHLY RELIABLE FOR SEPARATING SORGHUM LINES INTO
HIGH AND LOW TANNIN GROUPS. THE^ ACIDIFIED^ VANILLIN^ METHOD
0F TANNIN ANALYSIS DESCRIBED BY^ BURNS^ (1970)^ ESTIMATES^ TANNIN CONTENT AS CATECHIN EQUIVALENTS. (^) I SHOULD-EMPHASIZE (^) THAT THE
VALUES OBTAINED^ FROM^ THIS^ TE3T^ ARE^ BASED^ ON^ CATECHIN^ EQUIVA-
LENTS# NOT ACTUAL TANNIN-CONTENT. ROONEY^ ET^ AL,^ .(1972)^ AT TEXAS A & M HAVE REPORTED^ RECENTLY^ THAT^ CATECHIN^ EQUIVALENT
VALUES FOR^ GRAIN^ SORGHUM^ ARE^ CORRELATED^ WITH^ TANNIN^ VALUES
OBTAINED WITH OTHER METHODS.^ IN^ OUR^ EXPERIENCE^ THE^ RANGE^ OF CATECHIN EQUIVALENTS^ FOR^ SORGHUM^ IS^ FROM^^0 TO^ 10.^ WE^ HAVE
CLASSIFIED SORGHUM LINES AS LOW TANNIN IF THE CATECHIN EQUIVA-
LENT VALUE IS BELOW 1,00,
FREQUENCY OF HIGH TANNIN^ SORGHUM
GENEOTYPES IN THE^ WORLD^ COLLECTION,^ '^ WE^ HAVE^ ONLY^ LIMITED
EVIDENCE AT THIS TIME ON
THE FREQUENCY^ OF^ HIGH
TANNIN SORGHUM-GENOTYPES'IN^ THE^ WORLD^ COLLECTION.^ AMONG^ 472,
LINES WHICH^ WE^ HAVE^ ANALYZED^ FOR^ AMINO^ ACID^ CONTENT,^ SHOWN
ALKALI DEHULLING OF HIGH'ANDLow
TANNIN SORGHUM GRAIN, SINCE THE TANNIN IN SORGHUM GRAIN IS
CONTAINED PRIMARILY IN THE TESTA
LAYER BENEATH THE PERICARP, WE HAVE
TRIED WITH SOME SUCCESS TO REMOVE THE TANNIN WITH AN ALKALI
DEHULLING TECHNIQUE DESCRIBED BY DR, BLESSING (1971) AT THE USDA LABORATORY IN PEORIA, ILLINOIS, THIS METHOD INVOLVES
HOT SODIUM HYDROXIDE TREATMENT' OF THE WHOLE GRAIN FOR-6-
MINUTES FOLLOWED BY REPEATED WASHING WITH DISTILLED WATER,
THE DATA IN TABLE 7 SHOWS THE EFFECT OF DEHULLING ON TANNIN
CONTENTO PROTEIN CONTENT# RAT GAIN AND-FEED CONSUMPTION FOR
.oNE LOW TANNIN TEXAS HYBRID (RS610) AND TWO HIGH TANNIN LINES (iS6992) AND (IS8260) FROM THE WnRLD COLLECTION, CA-
TECHIN EQUIVALENT.VALUES WERE REDUCE' ,ITHOUT SUBSTANTIAL
CHANGE IN -PROTEIN CONTENT IN ALL.CASES, RAT WEIGHT GAIN WAS
NOT SIGNIFICANTLYIMPROVED (^) BY DEHULLING THE LOW TANNIN RS
HYBRID, BUT WAS SUBSTANTIALLY INCREASED BY DEHULLING OF BOTH,
HIGH TANNIN LINES, THERE WAS NO LARGE DIFFERENCE IN THE AMOUNT
.OF FEED-CONSUMED BETWEEN HULLED AND DEHULLED SAMPLES WHICH
I.N'DICATES THAT THE POOR WEIGHT GAIN FOR WHOLE. GRAIN SAMPLES
OF 1S6992 OR IS8260 (^) WAS NOT CAUSED BY (^) REDUCED INTAKE,
ALL OF OUR PREVIOUS TESTS ON THE DIFFERENCE IN RESPONSE
OF LYSINE SUPPLEMENTATION BETWEEN HIGH AND LOW TANNIN SORGHUM
LINES HAVE BEEN'MADE BY COMPARING LINES FROM THE WORLD COLLEC-
TION WHICH DIFFER IN TANNIN CONTENT BUT ARE NOT ISOGENIC FOR
OTHER CHARACTERISTICS, (^) A MORE DIRECT TEST-CAN BE MADE BY
12
UTILIZING THE ALKALI DEHULLING TECHNIQUE TO OBTAIN "LOW TANNI.N" CONTROL" LINES WHICH^ CAN-THEN^ BE^ COMPARED^ WITH^ WHOLE GRAIN WITH THE SAME GENETIC BACKGROUND BUT^ WITH^ A^ HIGH^ TANNIN
CONTENT, THE^ RESULTS^ OF^ AN^ EXPERIMENT^ COMPARING^ THE^ BIO-
LOGICAL VALUE OF WHOLE GRAIN SAMPLES FROM TWO HIGH TANNIN
LINES# AND DEHULLED COUNTERPARTS OF EACH^ LINEo^ WITH^ AND^ WITH- OUT LYSINE SUPPLEMENTATION^ ARE^ SHOWN^ IN^ FIGURE^ 7.^ IN^ BOTH CASES THE RATS GAINED LITTLE OR NO^ WEIGHT^ ON^ THE^ WHOLE^ GRAIN (HIGH TANNIN) RATIONS SUPPLEMENTED WITH^ LYSINE,^ BUT^ RESPONDED TO LYSINE SUPPLEMENTATION OF^ THE^ DEHULLED^ (LOW^ TANNIN)^ COUN- TRRPART.RATIONS. THE^ EVIDENCE^ FROM^ THIS^ AND^ OTHER^ STUDIES DISCUSSED DEMONSTRATES^ THAT^ LYSINE^ CONTENT^ IS^ THE^ MAJOR^ FAC- TOR LIMITING THE BIOLOGICAL VALUE OF LOW TANNIN SORGHUM GRAIN BUT IS NOT* FIRST LIMITING^ FOR^ HIGH^ TANNIN^ SORGHUM 1 ,
SUPPLEMENTATION WITH SOYBEAN MEAL. ONE POSSIBLE EXPLANATION FOR LACK OF RAT GROWTH RESPONSE IN^ LYSINE^ SUP- PLEMENTED HIGH TANNIN SORGHUM RATIONS IS THAT^ THE^ TANNIN COMPOUNDS MAY RRODUCE A TOXIC EFFECT WHICH COUNTERACTS THE EXPECTED GROWTH RESPONSE^ FROM^ LYSINE^ SUPPLEMENTATION,^ THE DATA IN FIGURE 8 SUGGEST THAT THIS IS NOT THE^ CASE^ SINCE^ THE ADDITION OF^ ONLY^ FIVE^ PERCENT^ SOYBEAN^ OIL^ MEAL^ TO^ HIGH^ TANNIN .RATIONS PRODUCED (^) A VERY SIGNIFICANT (^) INCREASE IN (^) RAT.GROWTH,
IN THIS^ EXPERIMENT^ CONDUCTED^ BY^ SCHAFFERT^ (1972)^ AT^ PURDUE, RATIONS CONTAINING TWO^ LOW^ TANNIN^ AND^ TWO^ RIGH^ TANNIN.'LINES
14
'ARE COMPLEXED WITH TANNINS (^) OR NOT. THERE ARE OTHER (^) POSSIBLE EXPLANATIONS-WHICHNEED (^) TO (^) BE TESTED'.- INCLUDINGITHE FOLLOW- ING: A) SOYBEAN MEAL (^) MAY PROVIDE SOME OTHER ESSENTIAL AMINO ACID WHICH IS SELECTIVELY (^) UNAVILABLE IN HIGH TANNIN RATIONS. B) THERE MAY BE (^) A DEFICIENCY OF AVAILABLE (^) INORGANIC NITROGEN, NEEDED (^) FOR BIOSYNTHESIS OF NON-ESSENTIAL AMINO ACIDS AND/OR OTHER (^) NITROGENOUS COMPOUNDS VITAL FOR NORMAL (^) GROWTH AND DEVELOPMENT# IN (^) HIGH TANNIN (^) SORGHUM RATIONS, PERHAPS (^) BECAUSE OF THE UNAVAILABILITY (^) OF THE NITROGEN FROM THE (^) SORGHUM
PROrEI N
c). THERE MAY BE COMPOUNDS (^) IN SOYBEAN MEAL WHICH CAN BIND (^) MORE COMPETITIVELY WITH TANNINS, (^) AND THEREBY REPLACE THE (^) PROTEIN BOUND TO TANNIN (^) MAKING IT MORE AVAILABLE, EACH (^) OF THESE POSSIBILITIES IS (^) CURRENTLY UNDER TEST IN SUMMARY, THE PROTEIN (^) QUALITY IN MOST GRAIN SORGHUM IS MARGINAL WITH REGARD (^) TO LYSINE CONTENT, AND IT (^) WOULD APPEAR THAT AMONG THE (^) HIGH TANNIN LINES ONLY A (^) PART OF THIS PROTEIN IS AVAILABLE-FOR UTILIZATION (^) BY MONOGRASTRIC (^) ANIMALS 1 WHAT IS THE STATUS OF OUR (^) EFFORTS IN IMPROVING THE NU- TRITIONAL QUALITY IN SORGHUM? (^) I HAVE ALREADY TALKED ABOUT THE TANNIN PROBLEM. IF 'WE ARE'CORRECT IN OUR ASSUMPTION THAT
TANN'INS COMPLEX WITH SEED (^) PROTEINS, (^) AND THAT THESE (^) PROTEINS
15
:ARE 1 AEN LES. -AVAILABLE ' MoNOGASTRIC'HEREARESEVERALAL
TERNATIVES':.
1) USE ONLY^ LOW^ TANNIN,^ ORGHUMS^ FOR^ CONSUMPTION^ BY
HUMAN AND OTHER^ MONOGASTRIC^ ANIMALS^ AND^ FIND.OTHL..
METHODS FOR^ CONTROLLING^ BIRDS. 1 WHICH^ IS^ ONE^ MAJOR
REASON FOR USING HIGH TANNIN SORGHUM GERMPLASM,
SINCE TANNIN CONTENT IS^ SIMPLY^ INHERITED^ AND^ CON-
TROLLED BY ONLY ONE OR^ TWO^ MAJOR^ GENES^ THIS^ IS AN
EASY TASK FOR THE BREEDER,
2) (^) USE HIGH TANNIN SORGHUM LINES FoR THEIR DESIRABLE
AGRONOMIC CHARACTERISTICS,^ AND^ PLAN TO^ SUPPLEMENT
WITH ADDITIONAL PROTEIN^ TOMEET^ THE^ NUTRITIONAL
REQUIREMENT, IF THIS APPROACH IS^ ADOPTED^ ONE
SHOULD BEAR IN MIND THEPOSSIBILITY^ THAT^ YOU^ ARE
ESSENTIALLY WASTING^ SOME^ OF^ THE^ PROTEIN^ IN^ THE
SORGHUM GRAIN$ I DO^ NOT^ BELIEVE^ THAT^ THIS^ IS
ECONOMICALLY FEASIBLE^ IN. MOST^ AREAS^ OF^ THE^ WORLD
WHERE SORGHUM^ IS^ A^ MAJOR^ COMPONENT-OF^ THE^ HUMAN
DIET.
3) (^) THERE MAY Bt:DEHULLING PROCEDURES OR METHODS OF
DRY MILLING THAT:COUL BE-USED TO REMOVE THEPERI-
CARP AND TESTA CELLS WHICH CONTAINTHE^ TANNIN^ COM-
POUNDS,
4): THERE MAY^ BE^ ADDITIVES^ THAT^ WILL^ PREFERENTIALLY
BIND WITH^ THE^ TANNINS^ AND^ ALLOW^ THE^ PROTEIN^ TO^ BE
UTILIZED,
17,
CONTENT OF ALL FIVE, LINES/ARE SHOWN IN, ABLE ?J IHESE ARE
IhELIMINARY RESULTS',AN, ARE VERY iNTERESTING FROM A THEO-
RETICAL POINT OF VIEW,L BUT IT IS TOO EARLY TO SPECULAT.:ON
THE PRACTICAL VALUE OF tHESE CARBOHYDRATE MUTANTS FOR IMPROV, ING .THE NUTRITiONAL QUALITY OF SORGHUM, THE PROLAMINE CONTENT OF SORGHuM ENDOSPERM IS HIGH, AS WE.HAVE SEEN, AND THE LYSINE CONTENT OF THE-,.PROLAMINE
FRACTION IS VERY LOW IN SORGHUM AS IT IS "ICORN, THE, sITU-
ATioN IN SORGHUM PARALLELS THAT IN NORMAL CORN IN MANY RE- SPECTS. THERE IS EVERY REASON TO BEL.IEVE THAT MUTANTS WHICH REDUCE OR BLOCK PROLAMINE SYNTHESIS ALSO OCCUR IN SORGHUM, WE IHAVE NOW COMPLETED EXAMINING SECTIONED KERNELS OF MOST LINES IN THE WORLD COLLECTION AND IDENTIFIED POSSIBLE OPAQUE KERNEL PHENOTYPES, SOME HAVE BEEN GROWN IN LAFAYETTE IN 1974 AND OTHERS (LIGHT-SENSITIVE LINES) ARE.BEING GROWN IN PUERTO RiCo THIS WINTER, PROTEIN AND LYSINE ANALYSIS OF THESE PUTA- TIVE OPAQUE LINES WILL REVEAL WHETHER ANY LOW PROLAMINE LINE HAVE BEEN IDENTIFIED. PRELIMINARY RESULTS OF TWO LINES FROM ETHIOPIA IDENTIFIED BY MR, RAMESHMh4R S.INGH ARE ENCOUR- AGING, THE PROTEIN CONTENT OF THESE LINES IS 12 AND 15 PER- CENT, WITH LYSINE CONTENTS OF 3.0 AND 219 PERCENT(EXPRESSED AS PERCENT;OF PROTEIN), RESPECTIVELY. DR. JAMBUNATHAN HAS JUST COMPLETED FRACTIONATION OF THE ENDOSPERN PROTEINS OF THESE". TWO LINES AND THE RESULTS ARE PRESENTED IN TABLE 9. NOTE T'HE, REDUCTION INI PERCENT PROTEIN IN THE PROLAMINE FRAC- TIONS; (^) II AND III) (^) AND THE INCREASE (^) IN P.ERCENT PROTEIN-IN
FRACTION'' WHICH^ IS,THE^ LYSINE"RICH^ FRACTION^ rIN^ SORGHUM,
D :T;A^ FROM^ A^ PRELIMINARY^ RAT^ FEEDING:^ TRIAL.OF^ ONE^ OF^ THESE^ LINES
COMPARED WITH OUR'BEST CHECK^ .LINE^ (IS2319)^ IS^ PRESENTED^ IN TABLE 10.^ THIS^ VERIFIES^ :THAT^ THE^ BIOLOGICAL VALUE^ OF^ ETHIOPIA 204-2 IS:INDEED SUPERIOR TO^ OUR-BEST'CHECK^ LINE.^ WE^ DO^ NOT
BELIEVE, AT^ THIS^ TIME,^ THAT^ THESE^ LINES^ FROM^ ETHIOPIA^ REPRESENT
THE.EQUIVALENT IN SORGHUM^ OF^ THE^ OPAQUE-2^ HIGH^ LYSINE^ MUTANTS
IN COrN MUcH^ MORE^ INFORMATION^ IS^ NEEDEDP^ BUT^ IT^ IS^ FAIR^ TO
CONCLUDE THAT^ THEY^ REPRESENT^ A^ STEP^ IN^ THE^ RIGHT^ DIRECTIONt,
IEl TOWARD^ BETTER^ NUTRITIONAL^ QUALITY^ IN^ GRAIN^ SORGHUM,
IN SUMMARY* IT^ WILL^ BE^ NECESSARY^ TO^ CONSIDER^ EACH^ OF
THESE PARAMETERS IN^ THE^ IMPROVEMENT^ OF^ NUTRITIONAL^ QUALITY^ IN
SORGHUM, IT ISUNLIKELY THAT^ ANY^ LINE^ IN^ THE^ WORLD^ COLLEC- TION WILL^ HAVE^ ALL^ THREE^ NECESSARY^ CHARACTERISTICS,^ IN^ MY
ESTIMATION WE^ WILL^ HAVE^ TO^ IDENTIFY^ LINES^ WITH^ EACH^ COMPONENT
OF NUTRITIONAL QUALITY^ AND^ THEN^ RECOMBINE^ THEM.TO^ OBTAIN
GENOTYPES WITH^ THE^ DESIRED^ COMBINATION^ OF^ CHARACTERISTICS,
