followingthe mating of Hoydeum jubaiumX
5βC超JβCβγβαね,壷∂グ♂.,29(1944).
(13)DAVIE,J…H.:Cytologicalstudiesin the
Muvaceae and certainrelated families,Jour
Gβ乃βfり28(1933).
(14)DAVIS,B」M.:The genetics and cytology of tetraploid from Oenoiheya jンansiscana
BARTLETI,G♂〝βffc.ざ,18(19:33)
(15)FoRD,C巾E,:A contribution to a cyto・
geneticalsurvey of the Malvaceae,Genetica,
20(19二37)
(16)FuKUSH∫MA,El:Preliminary report on βγα5SgCα一尺(ゆゐd和郎S hybrids,Pγ〃C.∫ククゆ,A躇d呵 5(1929)
(17)二l三l苗定昌:豪亜棉の倍数体並びにその性矧こ 就いて,樅及動,8(1940)
(18)GATES,RR.,GooDWIN,KM :A new
haploid Oenolhera with some consideration$
on haploidyin plants and animals,Jour.
Gβ刀βf.リ23(1930)
(19)GREGOR,J..W,,SANSOME,F‖Wり:Genetics of wild populationsII,′0〝γ‖Gβ〝βf,22(19:30)
(20)HAGERUP,0∴ Uber Polyploidie in Beziehung2;u Klima,Okologieund Phylogenie,
Chromosomen2:ahlenaus Timbuktu,Hkrediias,
16(1932)
C21)∴ :Studiesonpolyploidecotypesin
佑郎扉扁∽明視玖が撒.㍑弼1り蕗舶,18(1933)
(22)−州:Studies on the significance of polyploidyIl,Orchis,ibid。,24(1938)
(23)HILTNER,L,KINZELl,W.:Uber die
Ursachen unddie Besteitigung der Keimungs−
hemmungen bei ver・SChiedenen praktisch wichitigeren Samenarten,Nalurw.Zdts
(1940)
(12)一一− :Collapse of the seed
−82・−−
エα〝♂‖机F¢γ.S≠抑.,4(1906).
(24)rrUICHINSON,J.B‖:The genetic$Of cotton,
PaIt X,′0〝ダ‖C♂〝βg小,28(1936一)
(25)井上 頼数、阿部 定夫:メロンのコルヒチン 処理成績,]報,園雑,10(1939a)
(26)仙−【−− ,+ :ditto,IH報,植及動,7
(1939b)
(27)Jos=I,A,B.,HARDAS,M.W.:Chromos。me numbe工Of AbelmoschusiubeYCulaius,PAL et SINGH−A species related to the cultivated Bbindi,C狛明細ば5励庭那♂,22(1953).
(28)香川 冬夫:禾穀類の属問雑種の花粉形成過程 に及ぼす異常温度の影響,日作紀,8(1936).
(29)KAGAWA,F…:The effect of abnormal temperature on the course of pollen for−
mationina genushybrid7?iiicumcompacium X5βCαJ♂C−♂γ鋸南,ノ滋♪‖/∂鋸グ.β扉..,10(1939)
(30)香川 冬夫‥一二の種聞及び属間雑種の花粉形 成に及ぼす異常温度の影響,日作紀,12(1940)
(31)−¶:新作物「糊麻」に就いて,日本作物 学会講演会発表及び個人出版,(1944).
(32)金沢 林軌郷 正士‥林木人為倍数体の外部 形態の変化,遺雑,23(1948).
(33)KARPECHENKO,G.D‖:Hybrids ofL ♀ 月頃娩の傲SSα如〟SL.X βγα5√S去cα(姑汁皿形α〕L,
/0〝γいG♂〃βf‖,14(1924■).
(34)一一一山−−−.:Polyploid hybrids of Raphanus 封がわ勅S L..XβγαSS査α7∂J♂7βC♂αL..,ZβオブざCゐ7..古形d AみSf..祝いyβ7βγ∂〝乃gSgい,48(1928)
(35)KA,rAYAMA,Y..:The chromosomenumber in f〉ゐβSβOJ〟.S:and AgJ菖〝弼,and an obse工Vation On the size of stomatain differentspeciesof
rタf′fc〝∽,Jo〟γ… ScZ… Agグ,.S¢C.7七尾.γ〃,(303)
(1928).
(36)q−−:Crossing experimentsin certain Cereals with specialreference to different
compatibility between the reciprocalcrosses,
肋研.CogJ‖Agγリガプ〃fo∫郡久ロガれ(27)(1933)
(37)KEARNEY,T.H小:Self fertilization and
∝・OSS fe工・tilizationin PiTna COttOn,ぴい5βゆf 4㌢.β〝JJ。リ(1134)(1923)
(38)KIHARA,H.,KATAYAMA,Y :Genomanalyse beiTyilicum und Aegil(ゆSlI,Cyiologia,2
(1931)
(39)−−−.〜 ,NISHIYAMA,Ⅰ:Different cross−
abilityin reciprocalcrosses of Avena,With SpeCial refereIICe tO tetraploid hybrid$
between hexaploid and diploid species(The
geneticsand cytology of certain cerealsIII),/㊥/0伽γ‖β∂≠,り6(1932).
(40)木原 均,岸本 艶‥コルヒチン処理に依る倍 数性の鶏頭,農及園,13(1938).
(41一)劇 :小麦及びェギロブスのゲノム分析と その分類学的応用,退雑,16(1940).
(42)〝【 ,山田 倍平‥種間雑種の不稔に及ぼ すプラズマの影響,生研時報,(1)(1942).
(43)KoSTOFF,D小,KENDALI・,J・:Studies on
polyploidplantsIII,Cytogeneticsoftetraploid
七OmatO,G(Zグね乃わα〝彿言」S・S.,9(1934).
(44)一一山肌肝:Directed heritable varia七ions
conditioned by euploid chromosome alterr
atioIl$,′0鋸γ小G♂邦♂f.,36(19,38a).
(45)Ⅶ−−:Studieson polyploidplantsXXI,
Cytogenetic behaviour of the allopolyploid
hybridsNicotiana glaucaGRAH。ⅩN エαngS−doYjfii wEINN , and their evolutionary significance,Jour.Genei.,37(1938b)
(46)小谷 亮‥黄濁葵の疫病に関する研究,仁】柏病 報,17(1953).
(47)KUHN0。:DieHartschligkeitbeiLuPinus,
g匁カれAγC・カブび,9(1925)
(48)KuRIYAMA,H.,WATANABE,Y.:Studieson thebaploidplantsofβ川S・S査αZ(祝わ犯跡ね,育雑、
5(1955)
(49)桑田 晃ニトロロアオイの開花着掛こ関する研 究,(未発表).
(50)一− 【 :トロロー7■オイの突然変異体について,
(未発表).
(51)∵
:トロロアオイの品種について,(未発 表).(52)LAIBAC王王.F.:Ectogenesisin plants・,Methods
and genetic possibilities of prIOPagating
embryos otherwise dying in seeds,Jour.月壱7β♂,20(1929).
(53)LEVAN,A.:ZytologischeStudien anAllium Scゐ0β乃∂♪アαS〟∽,g♂γβdブfαS,22(19:36)
(54)LINDSTROM,E。W。,Koos,K :Cytogenetic
investigations of a haploid tomato andits
diploid and tetraploid progeny,AmeY.Jou7 βofり18(1931)ー・・・83一
作紀,16(1946).
(70)中村 迎こモロコシにおける気孔の大きさの薬 序による変異,育種研究,(2)(1943).
(71)西山 市三:倍数性の誘発とコルキシソの応用,
退維,14(1938a).
(72)w:コルキシソ法による倍数植物の育 成,植及動,6(1938b)
(73)−−:人為的倍数植物の研究(6報),園 雑,柑(1942).
(74)+− ,柄沢 博糞‥ditto(18報),トウガラシ における三倍性交雑不和合に就いて,育雑,3(1954).
(75)NISSEN,0.‥Spalteapingenes st6rrelsehos trillingplanter med ulike Kromosomtall,Boi・
∧わわ・Sβ乃,(1937)(Citedafter農学綜報,弗一朝,
1947).
(76)NoGIJTI,Y‖,OKUMA,KりOKA′H.:Studies
on the polyploidy in Nicotiana induced by the treatment with coIchicineI,General observations on the autotetraploid of
.Ⅳね加ゎ糀=嘲Sffcαand〃‖乃∂〃♂以弼,ルゆ..′0鋸γ β〃才…,10(1939).
(77)叫− ,0ⅩA,H小,OruⅨA,T.:dittoII,
GrowthIate andchemicalanalysis of diploid andits tetraploidinNicoiiana yusiica andN
71めαC祝研,£∂gd.,10(1940)
(78)野口 弥吉,菅原 友太:荷麦及び向日葵の同 質倍数体について,追雑,18(1942)
(79)農林省西条農事改良実験所壷井試験地:黄筍葵 種子の発芽温度に関する調査,黄萄葵試験成疏書,
(1947)
(80)岡 英人:蕃茄の倍数性に関する研究,2報,
倍数個体の生理的性質に就いて,園雑,11(1940).
(81)小野 知夫:二三雌雄異株植物の倍数体につい て,退雑,15(19二39)
(82) ト:倍数性醜豆の染色体倍加に伴う諸形 貿の変化について,栢及動,8(1940)
(83)尾崎 重夫:作物害虫精説,朝倉書店,東京
(1951)
(84)PAL,B‖ P,SINGI王,H,B‖,SwARup,Ⅴ。:
Taxonomic relationships and breeding possi−
bilities of species of Abelmoschus relatedto
Okra(A‖βSC〝gβ乃f〝S),占わ上G奴乙,113(1952)
(85)RANDOLPH,L F.:Cytogenetics of tetra−
pヱoidInaize,ル〝7.Agγ..忍βタい,50(1935)
(86)RosENBERG,0.:Theinfluence of low
(55)∵
,HtJMPHR苫Y,L.、M.ComparativeCytOgenetic studies of tetraploid tomatoes
from different origins,G@neiics,18(1933).(56)間島 勇雄‥テトラプロイト稲に・閲す−る二≡.の 観察,混雑,16(ユ940).
(57)MANTON,L:The cytologicalhistory of wateだCreSS(〃α.抽幻視郁々〃誠加舶R),Zgど才一 5Cゐ7.∫乃d.A∂.s≠.以..yβγβ㌢∂〝乃gSJ.,69(1935).
(58)松田 秀雄‥巨態花粉粒の生成に及ばす湿度の 影響に関する実験的研究,日作紀,8(1936).
(59■)松浦 一・:三倍性のフヂと細胞定数(Eutely)
の問題,植及動,5(1937).
(60)MEDWEDEWA,G..B‖:Karyologicalreview
of15 species of the genus Hibiscus,Jouy
β∂f、.(ねエ匂グーS.5.,21(1936).
O51)MICHAELIS,P.,:Entwicklungs−geSChichtlich・
geneti$Che Untersuchungen an
II,DieBedeutung desPla$maS紬r die Pollen−
feltilitよt des Ej}il(一bitI))1[z!(i?t[)7l・JliTSIt(tIl))Bast−
ardes,ZβZg.scゐ7一.∫乃d.A∂ぶf.臥Ⅴβタβア∂鋸符gSJ.,65
(1933).
(62)−:t5ber reziprok verschiedene
Sippenbastarde beiEPilobium hiYSutum VII,
Vergleichende Untersuchungen tiber das Plasmon der hirsutum Sippe Jena und die ihm
去bnlicbenPlasmoIle,吉∂言d‖,82(1948a).
ゆ3)−,BAKXER,D.:ditto,ⅤⅠⅠⅠ,Ⅴ併−
gleichendeUntersuchungenllberdasPiasmon
mehrer Ebilobium hilSulum−Sippen,die beireziproker Kreuzung unterscheideder Pollen
ferJtilit鈍才d摘.,82(1948b).
(64)−− :Uber Ab左nderungenderplasma−
tischen Erbgutes,ibid。,83(1949a)
(65)−‥Uberdie13eseitigung von Ent−
wicklungs−St6rungen auf dem Wege der
Plasmonab去ndeご・u昭,Z滋Cゐfβタ,19(1949b).
(661)MUNIZING.A。:Uber Chromosomenver−
mehrungin GaleoPsisMKreuzungen undihre
phylogenetische I∋edeutung,HeYedilas・14(1930)
(67)岬=Hybridincompatibilityandthe originof polyploidy,ibid,,18(1933)
(68)−−一山鱒:The evolutionalsignificance of autopolyploidy,f∂〜d.,21(19ご36)
(69)武藤 甲二:棉の花粉の発芽試験について,日
ー 84 −
temperature on the development of the embryosacmother cellin Loliumlongiflorum,
月毎′βd吉ねs,32(1946)
(87)佐々木睦男:普通小麦×ライ麦Flの花粉粒形成 に及はす異常温度の影響,日作学会講演会発表,
(1951)
(88)SAX,K.‥Therelationbetweenchromosome number,mOrPhological characters and rust resistancein segregates of partially sterile Wbeat hyb工ids,G卵㍑露お,8(1923).
(89)←
,SAX,H…Jり:Stomata si2;e and distributionin diploid and polyploid plant$,Jouy.Arnold.Arbり18(1937).(Cited after 学綜報,第→輯,1947)
(90)ScHL6ssER,LA.:Gren2;en und M6glich■
keiten der Ausnutzung vonPolyploidieinder Pflanzenz缶Cbt,ダ∂′,Sぐゐいβg♂〝.Sf,3(1937).
(91)SEARS,E.R.:Amphidiploidin the $eVen・
ChrOmOSOme7Ⅵ■わcf〝αβ,び元ね.且苅ざS¢鋸γi,Ag7.
五ゆ.S毎.尿路.β加〃リ(3′36)(1941a)
(92)仙:Chromosome pairing and fer−
tility in hybrids and amphidiploids in the 了ウifgc吉乃αβ,妨摘.りさ37(1941b).
(9二3)渋谷 常紀こ草根の花粉の発芽について,熱帯 農学会誌,2(1936)
(94)仙
:コルキシソ処理に】よる棉の長繊維種 の創生,農及園,15(.1940)(95)SHIMOIOMAI,N.:Zur Karyogenetik der Gattung Cゐγ.γS(Z乃≠如弼伽桝,J〃鋸γ..5cZ−月■fγ¢Sカi弼α
〃元わ‖ふ押」β.β血.2,2(19 33)小
(96)SKOVSTED,A:Chromosome numbersin the肋Jび離α♂Ⅰ,ノ〃〝′。.G I〝♂′り31(1935).
(97)−w−:dittoII,C..R.エα∂… C(7タJS.5.
タカ.ysわg.,23(1941).
(98)STILES,W。,DEuOW,M E.:Anoteonthe dormancy of the seed,Ann.Bot‖,38(1924)
(99)須藤 千春:日照の長短がルカウサウ属植物の 開花結実に及ぼす影響について,農及園,6
(1931).
(100)竹中 要‥倍数性と気孔の大きさとの関係 Ⅰ,
ギシギシ亜属植物に就いて,粗雑,55(1941)
(101)−Ⅶ−‥倍数性と器官の大きさ,年寄に気孔の 大きさに就いて,追碓,柑(194ご3)
(102)−一叫【一こ倍数性が示す形態的特致,殊に巨大 性の極限,農学綜報,第一胡(194L7).
(ユ03)田中 隆荘:自然倍数体と人為倍数体との細胞 容群の相違について,退雑,28(1953).
(104)田杉 平司,池田 義夫こ黄静葵の疫病,日楯 病報,9(1933)
(10S)TAYLOR,J.W.,QuISENBERRY,/Ⅸ.S.:Inq
heritanceofryecrossabilityiTIWheathybrid9,
∫0〝γ.A椚♂′.50CAgγ弼.,27(1935)
(106)TERASAWA Y.,SHIMOrOMAI,N…:Bastardq ierungsversuche beiByassica und R(ゆhanus,
ぶcZ・鋤・乃ゐ♂血′プ砂.ぴわれ,Ser.4,Bio王.3
(1928)
(107)寺沢 保房:体菜と大根との交配により育成し たるテーラプロイド雑種,追雑,7(1932).
(108)+一 :ブラシコラ■ファナスの形態に.就い て,日作紀,6(]934)
(109)TESHIMA,T.:Genetical and cytological
Studieson aninterspecific hybridofHib
βSC〝Jβ〝払s L・and g…〟α〃iゐ〃才 L.,ノb財.飽仁 4㌢.助舶αまゐ∫∽ク..び元知り34(1933).
(110)THOMPSON,W.P.:Shrive11edendospermin
SPeCie$ CrOSSeSin wheat,its cyto工ogicalCauSeSandgeneticaleffects,Geneiics,15(1930)
(111)知崎 良雄‥「あめりかねり」と「とろろあお い」との問における種間新型の育成,日作紀,8
(1934)
(112)戸拝 侃公:小麦とライ麦問め交配親和性,迫 雑,25(1950)
(113)内川 男‥疏兼摂における人為倍数体の研究,
第Ⅰ報,コルヒチン及びアセナフテン処理による璃 瓜四倍体の育成,生研時報,(3)(1947).
(114)UsTINOVA,E.Ⅰ.‥Interspecifichybridi2;ation
i王l地e genusガ塵∂∠ざ√〝J(Pr・elimi王遁ry(:Ommu王Ii−
cation),Gの紹〃α,19(1937).
(115)冊Ⅳ¶−:A descr・iption of theinter−
SpeCific hybrid of H…eSCulentus and H.
朗加繭扉,P沈粕お(〃df〝γ¢),6(1949)..(Cited afterア〜.βグee♂Aみ・Sまり2】(728)).
(116)WAGNER,S.‥ArtkrIeuZungeninder・Gattung 肋Jfα乃fゐ〝ぶ,Zβf≠,SCゐγい∫〝d‖Aみ5〜..〝りyβ7β7∂〝〝g5Jい,
61(1932).
(117)若桑俊二郎:小麦種問交雑における着粒歩合と 発芽能力との関係上遺雑,6(19:30).
(118)−岬− :小麦種同相反交雑における胚及び胚 乳発育の差異,道雄,8(193:3)
(119)WAKAKUWA,Sh..:Embryological$tudies
−85−
A∂Sf.鋸.yβγβγみ〝〝gSJ.,33(1924).
(122)+:屯ⅩperimentelleUntersuchungen 2;umArtbildungsproblem,ibid ,i4(1937).
(123)安田 貞雄:育種とホル・モン,台湾盛会報,2
(1.940).
(124)+:雌其の受精力保存期間について,植 及動,10(1942).
(125)+:種子生産学,養賢堂,東京(1948).
On the different seed−deYelopmentin req cipl・ocalinterspecific crossesin☆heat,JaP.
ノ〃㍑γいβ∂f..∴7(1934).
(120)WAIXINS,A。E.:Hybrid sterility 甲1d compatibility,′∂紛.G♂搾れ25(1932).
(121)WErTSTE‡N,F Ⅴ.:Morpbologie uI!d Physiologie des Formwechsels der Moose
auf genetischer GrundlageI,Zeiischl.Znd.
・−86−
Studies onthやInterspecificCrossingbetween Abelmoschus esculenius
MoENCH andA.肋nihoiMEI)IC.and theVarious Hybrids
andPolyploids Derived from theAbove Two Species
Hikaru KuwADA
R $nme
hthis paper,Variousprobledsin reia七ion to polyploidb士eeding werestudiedusingAbelmoschus CSCulenidSMoENCH(2n=124),A。ManihoiMEDIC‥(2n=68)and some polyploidsderived from them.
Atfirst,Studieswer・emadeinthe reciprocalcrosses betwe)en different varieties of esculenius and
肋nihoi,regar・diIlg the crossability,CauSeS Of completeor high sterilityin Flhybrids,themecha−
nism of feTtility and the charac七ers and meiosis of Flhybrids
Nex七,Studieswere extendedtothe fertilityof Nori−Asa (glutinous−hemp)(A。gluii720−icxiil KAGAWA)(2n=192),Whichisthe artificially rai$ed amphidiploid c工Op between the above two species,thedifferencesof physiologicaland ecologicalcharacteri$tics of 蝕is amphidipioidin
comparison with those ofits paTentS,the characters and meiosisin sesquidiploids obtained
between this amphidiploidandits two parents,aS Wellas the characters of seeds obtained and
the c=OSS COmpatibilityin the reciprocalcrosiSeSbetween this amphidiploid andits two parents.
Lastly the relation be七Ween thechromosomeconstitutionof plantsin regardto the chromosome setsof the parentsin the manifestation of quantitativecharacters of plants was studied… The plantsusedwereesculenius,Mbnihoi,theiramphidiploidりNori・Asa ,the工eCiprocalhybridsObtained amOngthesethreecropsas wellasfivekinds of polyploids derived from esculentus,肋nihot,
〃Nori−Asa=,りNori・A$a Xesculenius Fland Nori・Asa Ⅹ肋nihoiFl
l.T王IeerOSSabili七y be七ween A.¢ざe祝g¢花紬8and A.励花王ゐof,and抽e charac乞ers and meiosisimrecipTOCalFlhybTids be七ween七hem
(1)hescutenlus XMbnihoi,the%ofthe settingofpods was differentwith ぬe varieties of bothparents,rangingfIOmCa…27%to92%‖AveIagenumberof FISeedsper pod,thesizeand weight of FISeeds weredifferent acco工ding to the varieties of both paIentS.The germination
%of FISeedswas diffeIent With七he vaIietiesof motherplant,ranging from ca..2.7−83.3%.
(2)The set%of pods was higherin esculenius X A4bnihoithaninthe reciprocalcross.The number・SOf seeds per pod werelaIgerin escuteniがⅩManihoithanin thereciprocalcross,and these ntlmbers were smallerIeSpeCtively compa‡ed with thosein the mother plants which were
$elfed.The size of seeds obtai王1edi工IeSL3denius X肋nihoiwas smaller,While that obtainedin the=eCiprocalcross was similar,COmparedwith thatin the selfed mother
(3)Theappearance especiauy t壬】e CO工our of seed coat of FISeeds and their con七ent obtainediェI esculenius X ManihoIwere similar wi七h七hosein the selfed mother。Those of FISeeds obtained in the reciprocalc‡OSS Were mOStlylustrelss and scanty compaてedwith thosein the selfed
mother..The germination%of FISeeds and the success%of cross were extIemely higherin esculenlus X Mdnihoithanin the reciprocalcIOSS
(4)Thepollen tubeinesculenlus X肋nihoielongated speedily,penet‡ating the style by ca 90%ofi七sleI】gth within one hour after the pollination,Bu.t thepollen tube}in the recipr・OCal
CrOSS greW Silowly,penetr・ating caone halfitsleェ)gthin the same duration of time after the poliination
(5)There weIe SeVe工al characteI・S Which showedno diffe工enCe betweezlreCiprocalFlhybrid$,
ーー87−
Whilethe numbeIOf podsiIIFlhybrids of esculenius X MbnihoIwaslarger thanthatin the
reciprocalcross・The cytoplasimicinflueI】Ce Of the egg cellmay be animportant factor resulting in theinequality of reciprocalcrosses.(61)The%ofdyadcellsaswellasthat o王good pollengrainsinrecipzocalFlhybridswerequite high,nOdifferencesbeing obseIVedbetweenthem.Theseedfe=tilitYinrecipIOCalFlhybridswas extremelylow showing no difference.
(7)ThechIOmOSOmenumbersinroottipsofesculenius,Manihoiand reciprocalFlhybridswere 2n=124,68and96IeSpeC七ively・The meiotic divisionofPMCinthe parents wasIegulaI‖ tnreq
CiprocalFlhybrids,the restitutionnucleiwere foImedingreater pa=t Of PMCいAtImetaphase,
there were obse工Ved most frequently71I,and someirTegularities were also shown.Chromosome behavioTS appeared to be quite s如nilarir)IeCipIOCalFlhybIid$.
ⅠⅠ.The mechanisn of manifesta七ion of fertilityin Flhybrids
A.eざe〟ge花fαざ.XA.」肌∽純血
(1)InordertoeⅨaminethe mechanism ofmanifestaionof feItility,Studieswere made,Onthe effect of tIeating the meiotic courseof FlhybIidswith abnormaltemperatuzeonthe fo士mation
Of dyadcells,aS Wellas ontherelatioI−ShipbetweenthechIOmOSOmeCOnStitutionsofpollenand
the tissue of ovaTy.
(2)The%of dyad ce11formationin contTOIwas90%0= mOre,Whilethosein the mateIials treatedwithhigh,lowandal七eInatelychanged temperatu=eSWerell9−−82.4%,51。.9−72.6%and 55 OM66‖8%IeSpeCtivelylIThe%inmaterials treatedwith450cwas extremelylow.It seems thatinthe p】antin which extremelyhigh%ofthe formation ofdyadcells occuISinnormal
COndition,aSinthe caseinthe materialof thepresentstudy,theabnoTmaltemperature may results no effect on the formation of dyad cell$
(3)EachindividualofFlhybIidsesculeniusXMbnihotwasdividedintotwogroupsbycuttingand
OneOfthem was treatedwith coIchicine for chromosomedoubling,Whilethe other was remained
untI・ea七ed
The former showed good fertilityas∈血ownin Nori−Asa and F2 plants,but thelatter was
Sterile.The steIilityinFlhybrids eSCulenius X MbnihoIwas duetothe ratio ofthe number of
Chromosomesetinembryo,endospermandthetissue ofovarylInordertoincreasethefertility,
itmustbe desiredthat,Whenthe ratioof thenumber of chromosomesetinembryotothatin
endosperm was2:30r4:6,theonein the七issue of ovarywas notlor2,but20r4respectively.
ⅠII. Nori・・Asa and七he change Of fertilityinlater g・eIlerations
(1) No工i−Asa fi工St apPeared with bigh%ofca。96%inF2 plantsandkeptitself cons七an七in later genera七ions,Flp】ants and Nori−Asa showed heterosis.
(2)The fertility of Fl−FlO WaSStudied,the number of seedsper pod having been takenasindex
The averagefertility calculatedfor a number oflines of Fl,F2andF8is 6,2,29。2 and29‖2
grains per podIeSPeCtively,and that of F4,−FlOiscaい40 grains per pod for each generation,
Showingnolargeincreasewith the repetition of generationThefertility,however,differs more
Orlessin differentlines,reaChinginaline as far as48.O grains per podin F10.
IV.The differences of physiologicaland ecologicalcharacteristics of Nori−Asa in comparison with those ofits parents
(1)Charactersexamined weェe the germinationofseeds,effect ofsoildryness on plant growth,