Breeding and Cultivation of Japanese Species of Genus Coix as a Fodder Crop

By MICHIO MURAKAMI

Faculty of Agriculture, Kyoto Prefectural University

Juzudama and polyploidization with an aim Introduction of developing perennial fodder coix with high­ yielding potential. The genus Coix, believed to be originated in India and Southeast Asia, is a relative of Experimental results maize which belongs to Maydeae, and is one of the five oriental genera of Tripsaceae, i.e. The experiment was carried out at the Coix, Trilobachne, Polytocci, Sclemchne and Kyoto Prefectural University during a period Chionachne. Coix was cultivated in India in from 1955 to 1976. Results are summarized ancient days as indicated in Vedic literature as follows: (B.C. 1500-B.C. 800). It is now widely dis­ tributed over tropical, subtropical, and tem­ 1) Geogravhical ·varitaxonomy has been established yet. In phological characters. Juzudama showed a C. Lacry1na-Jobi L, seven varieties have been greater variation in plant height than Hato­ reported so far. Studies on the genus Coix mugi, ranging from 72 to 181 cm as compared have been confined only to morphological and to 115 to 148 cm in the later. Juzudama is cytological aspects,. ,1,'ls>. shorter in plant height at higher latitudes, In Japan, two major types of Coix have while such a tendency was not observed with been known, i.e. Hatomugi ( C. M. of pollen mother cells of the Ft plants 82% of the total number of cells examined showed 2) Pollen morphology 10 II, whereas 14% showed 9 II +2 I, and a As pollen morphology is a major field of few cells 4 I and 6 I. The occurrence of uni­ palynology, the surface structure of pollen valent chromosomes mostly due to the E chro­ membrane was compared with electron micro­ mosome is regarded the cause of the reduced scope among Hatomugi, Juzudama, F1 hybrids pollen fertility in F1 hybrids5>. between them, tetraploid Coix, and corn (Zea Mays L) with an aim of knowing the kinship 5) Segregation in F2 povulation of these plants. It was found that the sexine Early heading and late heading plants were of pollen membrane is covered by fine spinules, segregated with a ratio of 52 to 285, which and there is no recognizable difference in the leads an assumption that the time of heading surface structure among these plants, except is determined by 3 genes. Plant height show­ a slight difference in size and shape of spine, ed a trimodal distribution consisted of paren­ and a considerable difference in the structure tal and F1 modes (Fig. 2), indicating that of germ pores of pollens. This result suggests plant height is determined by a few genes with a considerable similarity among the species relatively large effectiveness. Penotypic and of Coix, as well as between Coix and Zea·1 >. genetic correlations between plant height and o~).ler characters showed that plant height has S) Characters of F1 plants hi°k h positive conelations with heading date, Seed fertility of Hatomugi and Juzudama leaf length, plant weight, and pollen fertility, was more than 90% in natural pollination, and but is negatively correlated with numbe1· of their selfing rate was proved to be as high as tillers (Fig. 3). As tall plants were all late­ 85% by isolated cultures. Interspecific cross­ maturing, the breeding for an early maturing ability between them was fairly high, showing tall type would be difficult. Winter-survival 43.1 and 50.3% in reciprocal crosses. Signifi­ ability was apparently greater with late­ cant heterosis was recognized in many char­ maturing tall plants than early-maturing acters of F 1 hybrids, especially with plant short plantsG>. height, number of tillers, leaf length and plant weight. In addition, the F1 plants showed par­ 6) F3 lines ticularly good regrowth after cutting, in terms From 43 F2-plants taken at random F:1 of plant height and number of tillers. How­ lines were derived. Mean plant heights of F:1 ever, the pollen and seed fertilities of the F1 lines ranged from 110 to 250 cm continuously. plants were only 60% and 30% respectively. Coefficient of variation of plant height was All the F1 plants survived winter in open smaller in tall lines, giving the correlation of field, and their growth in the next year was - 0.823 between plant height and the coeffi­ as good as in the first year. These facts cient of variation. Phenotypic and genetic cor­ suggest the usefulness of the F1 hybrid as a relations between plant height and some other fodder crop2>. characters were calculated by the analysis of variance and covariance. Plant height was 4) Cytogenetical features negatively correlated with number of tillers, Cytogenetical study was carried out to find but was positively correlated with heading out the cause of the decreased pollen fertility elate (Table 1). in the F1 hybrids. Both Hatomugi and Juzu­ Heritability of characters was estimated by dama have 20 somatic chromosomes with using correlation and regression between F2 karyotype formulae shown in Fig. 1. The individuals and F:1 lines and further by the shape of E chromosome is clearly different analysis of variance. Heritability estimated between the two species, and in the meiosis by correlation for plant height and for head- 58 JARQ Vol. 13, No. l, 1979

A Un11111111u111111 · Uuu11111111nn11

A I I I I I I I I I Length (11) IG. ,I 5. 3 ·1. 7 4. 5 4. 4 3. 9 3. 7 3. 7 3. 5 3. 3 Karyotype(<)= 2'·"'A••+213'" + 2C•• + 2"1>"' + 2"'t"' + 2F1m + 2F,"' + 2f',•• + 2G" + 211" B I I I I 3. 2 I I 4.0 3.4 3.5 (11 ) I 3.8 Length IG. 3 I 5. 4 4.I 9 4. 2 4. 5 Karyotypc(<)~ 2'·"'A"'+2U•• + 2C"' + 2

Fig. I. Somatic chromosomes and karyotype of Hatomugi (Coix Ma­ yuen Roman.) and Juzudama (Coix Lacryma-Jobi L.) A: Hatomugi, B: Juzudama

20

15 >. Q C "'::, <:r ~ 10 tt.. H 5 'I •I ' ' 1• ----, ' 0 ... - ' 100 150 200 250 Plant height (cm) --- C.M. - F2 (C.M. X C.L.) ··-• ···· C.L. ----- F2 (C.L. X C.M.) Fig. 2. Frequency distributions of plant height of Hatomugi, Juzudama and F2 populations C.M.: Hatomugi, C.L.: Juzudama 59

Fz (C. M. xC. L.) 0.214° Number of - 0.301·· F -0. 374 - Plant height, 0. 237 --Pollen fertility tiller's -0. 015 -0.009 ~ I 0. 763 .. 0. 725° '-0. 095. 0. 522 .. 0. 841 0.741 0.097 0. 532 0.211 0. 658 0. 130~ -0. ~18 I Heading date Leaf length rSeed fertility I 0.599.. 0.699° 0.630 0.831 0. 455 0.407 / I ~P-la_n_t _w_e_i_g_h_t I Leaf width

F1 (C. L. x C. M.) 0.211•• Number of -0.162* -0. 199 - - Plant hei~ht 0. 236 ····- Pollen fertility tillers - 0.015 - 0.009 I I 0.752.. ~ 0. 8,11 .. ~ -0. 008 0.487•• 0.806 0. 843 - 0.015 0.494 /,,,...... 0.211 0.658 0. 1:10 -0.018 .------~ I I Heading date Leaf length Seed fertility

I 0. 705 .. 0. 698 .. 0.736 0. 845 0.455 0.407 I Plant weight Leaf width

Fig. 3. Phenotypic, genetic and environmental correlation coefficients between main characters of F2 population Each set of three figures indicates phenotypic, genetic, and environmental correlation coefficients in that order. * Significant at the 5% level ** Significant at the 1% level

Table 1. Phenotypic, genetic and environmental correlation coefficients between plant height and some other characters of F3 lines

Correlation Plant height-No. of tillers Plant height-Heading date Plant height-Seed fertility rp -o. 6421** 0.8799** o. 1688 •G - o. 8931 0.9477 o. 1845 'E - o. 4948 0.4374 0.2274 'P, 'G and 'E show phenotypic, genetic and environmental correlation coefficients respectively ** Significant at the 1% level. 60 JARQ Vol. 13, No. 1, 1979 ing date was very high, i.e. more than 0.8 Tsble 2. Heritability calculated by means of for both cases. Heritability of number of correlation snd regression between F3 tillers was 0.5, but that of pollen and seed individual and F.1 lines fertility was hardly recognized because of re­ Character Con-elation Regression coefficient coefficient covered fertility in Fa plants. Thus, it is ex­ Plant height 0.3532* 0.3679* pected that tall, late-maturing and high-yield­ Number of tillers 0.4797** o. 1742** ing lines can be obtained in later genera­ Heading date 8116** 0.9945** tions1 0> . o. Pollen fertility 0.4902** 0.4494** Seed fertility o. 5663** 0. 3815** 7) F',1 and F'r, lines By selecting tall individuals of tall F:i lines, ** Significant at the 1% level. 51 F4 lines were obtained. Plant height vari­ * Significant at the 5% level. ance in F-1 line was generally smaller than in Fa, and the segregation of plant height emerg­ ed only in few lines. Phenotypic and genetic Table 3. Heritability calculated by means of con·elation between plant height and heading correlation and regression between F,1 date was highly significant, but the negative individual and F$ lines correlation between plant height and num­ Character Correlation Regression ber of tillers observed in early gene1·ations coefficient coefficient was not recognized in F.,. Heritability esti­ Plant height 0.2565 0.3448 mated by correlation and regression between N\!mber of tillers 0.2820 o. 1274 F:i and F4 plants was high for many charac­ Heading date 0.4981** o. 4211** ters, especially for heading date (Table 2). PoJJen fertility 0.2884 o. 1140 Among F,1 plants appeared many promising Seed fertility 0.2421 o. 1232 lines that are tall and fixed for plant height. ** Significant at the 1% level.

K.~b •.. Plate I. 'Tall F) lines developed from the interspecific hybridization between Hatomugi (Coix Ma,yuen Roman.) andJuzudama (Coix Lacryma-fobi L. ), as compared to Hatomugi, a short plant in the right side. Length of the measure shown is 200 cm. 61

Most of Fu lines obtained through a more Hatomugi were irradfated by X-rays of 5- intensive selection for plant height in F,1 20 kr. Judged from the effect of the treat­ seemed to have been fixed already for plant ment on seed survival and germination rates, height, in spite of the open pollination within plant height and seed fertility, it can be con­ F-1 lines (Plate 1) . Mean plant height for all cluded that 2X F1 is most resistant, and 4X the F6 lines was taller than that for all the Hatomugi and 4X F1 are less sensitive than F-1 lines. In the F., generation, a high corre­ 2X Hatomugi and JuzudamaS>. lation of 0.67 was still recognized between plant height and heading date, but no co1Tela­ 11) Cutting experiment tion was observed among other characters. Hatomugi, Juzudama, a F4 line of their Heritability was recognized for heading date, hybrid, and 4X FL plants were subjected to but not for other characters (Table 3). Seed the cutting treatment, by which plants were germination ability was increased to more cut 1- 4 times during their growth period. As than 80% with the advance of generation, so the cutting was repeated, the number of tillers that promising lines can be propagated by was increased in all plants, but it was most seeds Ill. remarkable with the F.1 line and Juzudama. Regrowth as expressed by plant height and 8) Polyploicl puints weight of harvests were greatest with the F4. To evaluate polyploid breeding, autotetra­ line. Total harvest weight in a growth pe· ploid Hatomugi and allotetraploid F1 of Hato­ riod of the F,1 line amounted to 7,100 kg per mugi X Juzudama were produced by the col­ 10a, which is as much as twice that of chicine treatment. The autotetraploid Hato­ pa1·ental species (Fig. 4). Two to three cut­ mugi showed a slower growth than the diploid tings during a growth period seemed to be one, and was inferior with all important char­ most effective. acters at the maturity, suggesting that the Chemical composition of the harvests was polyploidy is of no value in the breeding of determined at each cutting. Crude protein Hatomugi. On the contrary, the allotetraploi the use as a fodder crop3>. 12) Res-ponse to plcinting density 9) Resistance to sitbmersion Hatomugi, Juzudama, and a Fu line selected Submersion resistance of the allotetraploid, for tallness were grown at 3 levels of mix­ the two parent species, and their diploid F1 planting (30, 60 and 90 cm spacing). At a hybrid was compared. All of the used materi­ dense planting, plant height increased, but als, except Hatomugi, were highly resistant to number of tillers and dry weight/plant were submersion7>. decreased rema1·kably. Differences in the re­ sponse among three materials used were not 10) Sensitivit11 to radioactivity clearly recognized, but short plants were liable Dry dormant seeds of Hatomugi, Juzudama, to be influenced by tall plants. The dense diploid and tetraploid F1 plan ts, and tetraploid planting gave a greater harvest due to the in- 62 JARQ Vol. 13, No. 1, 1979

0 0 0

0 0 00

.-.. 0 .!':J 0 ;; 'D .!:P., 0 0 :I' ~ 0 0 I>.~ N

0 (I) (2) (1)

2 3 4

No. of cuttings

ffl Hatomugi, 11 Jujudama, I F, line, rn allotetraploid F1 plants Fig. 4. Weight of harvests at each cutting of Coix species and hybrids creased number of plants, although the dry Lac1-ym,a-Jobi. Morphologie de cette petite weight/plant was less. It suggests that a cereale et etude de sa plantule. Rev. lnter-nat. relatively dense planting would be needed for Bot. Appl. Agric. Trop., 31, 197-211 (1951) . 2) Murakami, M. & Harada, K.: Studies on high yields. the breeding of genus Coix. I. On the F 1 In addition to the above-mentioned studies, plants of intel'specific hybridization: Hato­ the author has undertaken the following mugi, Coix Ma-yuen Roman. Juzudama, C. works: Morphological and cytological studies Lacryrna-Jobi L. Sci. Rep. Kyoto Pref. Univ., of F1 hybrids between Thai and J apanese Agr., 10, 111-120 (1958) [In Japallese with English summary]. Coix varietiesH>, productivity of improved 3) Murakami, M. & Harada, K.: Studies on varieties in direct sowing culture15>, and per­ the breeding of genus Coix. II. On the formance of new Coix strains under submerg­ tetraploid plant of genus Coix induced by ed conditionto >. colchicine treatment. Sci. Rep. Kyoto Pref. Univ., Agr·., 11, 1-8 (1959) [In J apa.nese with English summary] . Conclusion 4) Murakami, M. & Takeoka, M.: Studies of the breeding of genus Coix. III. On the sur­ The use of the genus Coix as a fodder crop face st1·ucture of pollen membrane of genus is considered to be very promising, but many Coix and Zea. Sci. Rev. Kyoto Pref. Univ., problems still remain to be solved : genome Agr., 11, 9-14 (1959) [In Japanese with English summary]. analysis and combining ability for the better 5) Murakami, M. et al.: Studies on the breed­ use of heterosis, methods of selection in breed­ ing of genus Coix. IV. Cytogenetical studies ing, improved cultural practices, etc. Collec­ of Hatomugi (Coix Ma-yuen Roman.), Juzu­ tion of foreign genetic stocks is also needed. dama (Coix Lacryrna-Jobi L.) and its F 1 hybrid. Sci. Re7>. Kyoto Pr·ef. Univ., Agr., 12, 11-18 (1960) [In Japanese with English References summary]. 6) Murakami, M.: Studies on the breeding of 1) Mimeur, G.: Systematique specifique du genus Coix. V. Genie segregation in F2 gen­ gerne Coix et systematique val'ietale de Coix eration between Hatomugi ( Coix M a-yuen 63

Roman.) and Juzudama (Coix Lac1vn1,0,-Jobi [In Japanese with English summary]. L.). Sci. Rep. Kyoto P1·ef. Univ., Agri., 13, 12) Murakami, M. et al.: Studies on the breed­ 1-9 (1961) [In Japanese with English sum­ ing of genus Coix. XI. Competitive effect due mary]. to density of planting and mix planting. 7) Murakami, M. et al. : Studies on the breed­ Sci. Rep. Kyoto Pref. Univ., Agr., 17, 15-26 ing of genus Coix. VI. On the submersion (1965) [In Japanese with English summary]. resistance of some Coix varieties. Sci. Rep. 13) Murakami, M.: Studies on the breeding of Kyoto Pref. Univ., Agr., 13, 10-15 (1961) genus Coix. XII. Geographical variation of [In Japanese with English summary]. some characters of Hatomugi (Coix Ma-yuen 8) Murakami, M.: Studies on the breeding of Roman.) and Juzudama (Coix Lae1v1na-Jobi genus Coix. VII. X-ray sensitivity of Coix L .). Sci. Rev. Kyoto Pref. Univ., Agr., 18, varieties and segregation of characters of F2 1- 7 (1966) [In Japanese with English sum­ generation between Hatomugi (Coix Ma-yuen mary]. Roman.) and Juzudama (Coix Lacryma-Jobi 14) Murakami, M. et al.: Studies on the im­ L.) in the X2 generation. Sci. Rev. Kyoto provements by means of breeding of the Pref. Univ., Agr., 14, 1-11 (1962) [In Japa­ genus Coix. XIII. Morphological and cyto­ nese with English summa1·y]. genetical studies of F1 hybrids between Thai­ 9) Murakami, M. et al.: Studies on the breed­ land and Japanese Coix varieties. Sci. Rev. ing of genus Coix VIII. The relation between Kyoto A·ef. Univ., Ag1·., 21, 1-11 (1969) cutting numbers and grass yields of Hato­ [In Japanese with English summary]. mugi (Coix Ma,-yuen Roman.), Juzudama 15) Murakami, M. et al.: Studies on the im­ ( Coix Lac1vma-Jobi L.) and some breeding provements by means of breeding of the strains. Sci. Rev. Kyoto Pref. Univ., Agr., genus Coix. XIV. On the productivity of 15, 1-11 (1963) [In Japanese with English improved variety of the genus Coix in direct summary]. sowing culture. Sci. Rev. Kyoto Pref. U1iiv., 10) Murakami, M. et al.: Studies on the breed­ Agr., 23, 1- 9 (1971) [In Japanese with Eng­ ing of genus Coix. IX. Variation and herita­ lish summary). bility of some morphological characters of Fa 16) Murakami, M. et al. : Studies on the im­ strains between Hatomugi (Coix Ma-yuen provements by means of breeding of the Roman.) and Juzudama (Coix Lac1v11w-Jobi genus Coix as fod