68 



THE AGRICULTURAL NEWS. 



Masch 8, 1919. 



dMTSS ON INBERITANCB IN TBK 



OOWPEA. 



Mr. S. C. Harlaud B.Sc, has furnished the follow- 

 »ot€s in conchision of liis investigations ou inheritance 

 of characters in the cowpea: — 



A SYSTEM OF MULTIPLE ALLELOMORPHS. 



A paper by the present writer entitled 'Multiple Allele 

 BBorphs in Vigna' has been contributed to the/aur/ia/ of 

 Gtnetics. This paper has not yei been published, but it, will be 

 eoDVenient to ^ive a summary of the facts recorded therein, 

 and then to j^iie a sb.>r resume of further experiments 

 which have since .!een made 



It has been shown {Agricultural News, January 

 25, 1919) that the black colouration of the seed coat in 

 cowpcas is due to a factor, 15, alielomorphi? to its absence, and 

 apparently dominant over all oiiier seed coat colours. B also 

 manifests itself by the production of a purple tip to the 

 young pfxl, and by the development of a varying amount of 

 anthocyanin pigmentation in u*lyx and pedunt-le. In the 

 absence of h, the seed is devoid or black, and the young pod, 

 calyx, and peduncle are unili:irinly green. Thu", in crosses 

 inTolving B and its corresponding allelomorph, it is possible to 

 pick ont all the black-seedeu plaots by siiuple in.»pection of 

 the calyx or yonng pod. 



There is another factor which affects the tip of the young 

 jM and also the calyx and peduncle in a similar manner to B. 

 Mis factor, P, has apparently no effect on the seed-coat colour, 

 but it cau^es the uniform pioduction of an intense purple 

 colour in I he ripe pod P is alleJomorphic to its absence, i c. 

 to the same type that is the reces.site of B. 



Kxp»riment.s were carried ou' to determine the relation 

 of B to P. The following is a summary of the results: — 



Cio.S3 — B (Black in seed-coat, young pod piirplt tipped, 

 calyx and peduncle reddened) byP (No black in seed-coat, 

 young fKi.l purple ripped, calyx and peduncle reddened, ri[je 

 pod ni.iroon). 



The / , . 



The F, plants had the following c' aracters: black 

 seed, purple tipped pod, reddeneJ calyt and peduncle, and 

 maroon ripe pod 



Tlit F... 



Iri F.;, both the parental types appeared, together with 

 the 'i', type, but no farther combinations were pn duced. 



^amilie.s. Plant?. B P. B p. h P. 



7 -273 168 40 K) 



Here the ratio of B to b is 208 to 60, with expectation 

 20r» t.. t> on a ."' to 1 basis. The ratio i.f P to p is 23.3 to 

 40 with, e»peciation '20h to 6S. 



Tfu >;. 



Forty two families wrre grown in F ,. The results 

 Mr<> tabulated below: — 



I'heaotypi',- Xumbtr Xamber 



H I'. 



Y. ,,. 



181 



•f 



plants. 

 hryS 

 181 



i.u.'io 



Klp»f,Ulit.D on i : 1 : 1 rati?, 2'^ : l.';9 ; ).';!^ 

 tialio B t<. b 4.34 ; \2-: 

 V I.J p 427: ,2;^ 

 Kxpcctatiori 417 )3^ 



form <•! of 



' F.. jtareiit. fainiliee. 

 B r 14 



B p .0 



b !■ -j; 



b P. 



i.im 



The main point brought out by theabove table is that is 



IS impossible to get a plant homozygous for both B and f, i.e. 

 these two factors completely repeFeach other in gametoceneaiB 

 On th6 chromosome hypothesis of Morgan aM 

 his associates, the genes B and P are assoraed either to 

 occupy identical loci in' homologous chromosomes or to occupy 

 loci so close together that cros.^ingover does not occur- 



Kr.I>AT10N rtV THE NIW KRA l-ACTi«R E TO THt: FACTOR KOR 

 BL.<OK, K. 



In a previous note by the present writer an accouni was 

 given of the New Era factor, E. This factor is allelomor- 

 phic to the type which has just beei^ refeued to as allelomor- 

 phic to B and to P. E manifests itself by the production of 

 the characteristic New Kra pattern ou the seed coat, and also 

 by a similar, but less intense reddening of the calyx, peduncle, 

 and tip of young pod, to that produced by B-and P. 



A cross wa,8 made between Black iB) and New Era (E). 

 The Fj showed complete dominance of P., while in the F.^ the 

 ratio DBE : 3Be : .3 : Ibe was not nutained. Segregation 

 occurred into Black and New Era in the 3: 1 ratio, the numbers 

 obtained being 81 B'ack and i'l New Era (expectation 

 83 ^S:-" "5). The relation between It and E is thus similar 

 to that between B and P, i.e. B and E behave as an alleloroor- 

 phic pair 



Sioianan' and disiiission. 



Three factors — B, P, and K — have been shown to Ik; 

 dominant and allelomorphic lo the triple recessive type bpi- 

 Complete repulsion exists beiween \'> and P, and between 

 B and E, i.e. these pairs of factors behave as though 

 allelomorphic. The condition" are thus fulfilled for a 

 ijuadruple .system of allelomorphs analogous to the quad- 

 niple mouse series, and to the septuple Dro.sophila series. 

 The in<'si striking feature of the prc<ent c is- "s that the three 

 dominant genes B, P, and E, all manifest tlicmselves by ihf 

 production of anthocyanin colouration in calyx, peduncle, and 

 tip of y ung pod. 



CHLOROSIS OF SUGAR-CANE 



In an article contributed lo "he IVesl Iruiian Hulitlin 

 Vol. XVI, p. 137, Dr. H. A. Tr.upany, D.Sc, recordAd 

 results of his investigations on what are known in Antigua, kM 

 ■gall patches', which are unable to grow satisfactory crops of 

 sugar-cane, the <;ancs pUnlcd on thttn usually assuming a 

 characlerisiic cfcloroiir apfcarance, jod frequently dying .iiu. 

 itftera lime. Tbi-.so [jatchfs occur in the limestone districts, 

 nf Antigua but examination of the .soil gave definite evid»'nce 

 that gall patches were not duo, as has beeu .suggested, to the 

 presence of an ccettsive amoiiut of calcium carbonate. Tbe 

 res:iltM ol l.)r. Tcmpatiy"s txper.iiienls led liini to the couclu 

 sion th«t the chlf>r )«s nf plant.-*, especially canes, m -^ncli 

 pat.;lies was ilue to the presence ut sodium carbonate in the 

 S'lil, the origin of this sodium rarb(inate being attributable m 

 iniersviion between the crtloium c>trbonatc and the sodmm 

 I'tloriiie dis.vdved in soil water, tad brought up from salioi- 

 teiouv deposiisat dre|>er levels. 



In the Keport of the Porto Kico Agricultural l'"x{)eri- 

 .i.ent >5laiion 11)17, .a.seriesof siimliire.vperiinents onchlf)rosi» 

 '.1 s ipar cme is des'vibed and discussed. In the southern 

 parl^. i)t the is and ttjere are numerous .ireas, varying in size 

 friMii A few s juaro yards lo an acre or more, where sugar-cane 

 •■.ufl^-rH m'ue iir le-s from chlorosis. 



In ibc iii'nf, pr'«)()'tnwil i:,i'<i's of this chliTo^is the leivei* 

 art' of nonna! sj/t but creamy while in coloor: Oanes m, 



