J. Japan. Soc. Hort. Sci. 60 (4) : 921 — 926. 1992.

Resistance of Non-tuberous Solanum to Root-knot Nematode

Mohammad Ali, Naotaka Matsuzoe*, Hiroshi Okubo and Kunimitsu Fujieda Laboratoryof HorticulturalScience, Faculty of Agriculture,Kyushu University, Hakozaki, Fukuoka 812

Summary Resistance of eggplant, its wild relatives, interspecific Solanum hybrid and amphidiploids to Meloidogyne incognita was evaluated through inoculation of seedlings and grafted- and non- grafted plants. Immunity or high resistance was observed in S. khasianum, S. torvum and S. toxicarium. Small swellings were formed in S. sisymbriifolium; however, nematode matura- tion/egg production was not attained. The susceptible factor of the grafted scion was not transmitted across the graft union to the rootstock. Eggplants, S. integrifolium, their hybrid and amphidiploids, and S. indicum failed to show resistance against the root-knot nematode. Solanum mammosum and S. surattense were highly susceptible to M. incognita.

that nematode resistant tomato rootstock became Introduction susceptible, upto a certain extent, when suscepti- Root-knot nematodes (Meloidogyne spp.) cause a ble tomato (as scion) was grafted on the resistant severe damage of eggplant (Solanum melongena), one. The present study was undertaken with the especially in tropical countries (7). Expensive objective of confirming the precise reaction of the chemical control measure can be taken for the selected commercial eggplant cultivars, their wild time being. Long term and effective means to con- relatives, interspecific Solanum hybrid and two am- trol this soilborne pest are to develop resistant cul- against root-knot nematode with phidiploidsand tivars. In eggplant, there is no resistance against without grafting a susceptible eggplant as the root-knot nematodes (4). Yamakawa and Mochizuki scion. This study will provide information useful (19) and Fassuliotis and Bhatt (5) reported two for utilizing nematode resistant wild Solanum spe- wild Solanum species resistant to the pest nema- cies as rootstocks for eggplant and tomato produc- todes. Many of the wild Solanum, interspecific tion. This report will also provide information for Solanum hybrid and newly developed am- interspecific sexual and somatic hybridization to phidiploids (2), which are prospective rootstocks develop eggplant cultivar or suitable rootstock with for eggplant and tomato, have not yet been high degree of multiple disease resistance along screened against root-knot nematodes. with other desirable characteristics. Use of wild Solanum as rootstock of eggplant to Materials and Methods exploit their soilborne disease resistance is com- mon in Japan (15) and Puerto Rico (16). This is be- 1. Seedling test cause gene transfer from most of the wild Solanum Two cultivars of eggplant (Solanum melongena L. to eggplant through breeding is difficult or impos- Senryo 2 gou' and 'Uttara'), eight wild Solanum' sible (10). A high possibility of exploiting bacteri- species, an interspecific hybrid (S. integrifolium x S. al wilt resistance of wild Solanum through grafting melongena, a commercial rootstock for eggplant), tomato has also been demonstrated by Matsuzoe et and two newly developed amphidiploids (see Table al. (11). Ishibashi and Shimizu (8) demonstrated 1) were evaluated for their resistance to root-knot nematode. Nematode egg-masses were collected from galls of infected S. integrifolium plants grown Received for publication 14 June 1991. * Present address: Faculty of Agriculture , Kagoshima in an open field. All of the above materials were University, Korimoto, Kagoshima 890. inoculated with nematode at seedling stage, 38 to

921 922 M. ALI, N. MATSUZOE, H. OKUBO AND K. FUJIEDA

40 days after seed sowing. 10 each of grafted and non-grafted plants (Exp. II) 30 and 35 days, respectively, after inoculation. A 2. Test of grafted and non-grafted plants number of plants were monitored once a week af- On the basis of the results of the seedling test, ter inoculation to estimate the rate at which infec- Senryo 2 gou' was cleft-grafted on five of ' the tion occurred. Data is calculated as the percentage above Solanum stocks 61 days after their seeds of plants with galls. were sown. Solanum khasianum was not used in 6. Identification of nematode this trial because it is susceptible to Pseudomonas solanacearum E. F. Smith (M. Ali, unpublished Twenty galls from each plants of 'Companion' data, 1990). Inoculations were made 96 to 99 days and S. sisymbriifolium and only five each from S. after stock seeds were sown when the grafting torvum and S. toxicarium (on account of low infec- was deemed successful. Non-grafted plants of the tivity) were collected. The galls were fixed in 5% same age were concurrently inoculated. Nematodes formalin solution, treated by hot lactophenol solu- of these inoculations were collected from galls tion containing 0.01% fuchsin, and cleared in stain- formed on roots of seedlings from the previous ex- free lactophenol solution. The galls were excised periments. under a dissecting microscope and the female adults were examined for their perineal pattern for 3. Preparation of inoculum species identification. Egg mass from the galls of infected roots were Results and Discussion collected by hand and/or by shaking the infected roots in 10% sodium hypochlorite solution as The nematodes were identified as Meloidogyne recommended by Jatala (9). After thoroughly rins- incognita Chitwood by the perineal pattern of ma- ing with distilled water, the eggs were transferred tured adults in galls of all the Solanum species onto a 30 p.m nylon mesh floating on water in a studied. Petri dish and kept at 25°C. After two or three Experiment I days of incubation, newly hatched nematodes were collected. Seedlings, 38- to 40-days old, were in- Seedlings of S. khasianum, S. torvum and S. tox- oculated with 200 nematodes suspended in 2 ml of icarium were found to be immune (Fig. 1) to root- water, whereas grafted and non-grafted plants, 96- knot nematodes because no galls were formed to 99- days old, were inoculated with 1,300 nema- (criteria of Jatala, 1981). Yamakawa and Mochizu- todes suspended in 4 ml of water. ki (19) also reported the resistance of S. torvum seedlings inoculated with chopped galls. Solanum 4. Inoculation sisymbriifolium was invaded by nematodes which Seedlings were grown in 9 cm (diameter) plastic formed four to five distinct swellings rather than pots, and grafted and non-grafted plants were galls. The nematodes did not develop beyond the grown in 11.5 cm pots containing heat sterilized second juvenile stage in these swellings, and there- sand. Inoculation was done by pouring the inocu- fore, there were no egg masses. A similar obser- lum into two depressions on the surface of the vation was also reported by Fassuliotis and Bhatt sand near the root of seedlings. Twelve to 15 (5) in this species. They also reported that the plants of each entry were inoculated and each ex- nematodes in the swellings could not develop fur- periment was repeated twice. Control plants were ther after invasion because of tracheid discontinui- treated with sterilized water. Experiments were ty, due to the formation of a small, thin-walled carried out in a glasshouse during September to giant cell. Therefore, this species was also consi- December 1990. Average maximum and minimum dered to have a certain type of resistance mechan- temperatures of the glasshouse during the study ism against root-knot nematode. The eggplant were 29° ± 2•Ž and 21° ± 3•Ž, respectively. cultivars, 'Assist' (F1), 'Companion' and 'Compan- ion 2' (amphidiploids), and seedlings of S. indicum 5. Data collection and S. integrifolium were highly susceptible to M

Data on the occurrence of galls and their num- incognita. The two species with the maximum ber were recorded from 10 seedlings (Exp. I) and number of galls per plant were S. surattense and S. 923 RESISTANCE OF NON-TUBEROUS SOLANUM TO ROOT-KNOT NEMATODE

Fig. 1. Number of galls present on roots of 38- to 40-day-old seedlings of Solanum genotypes after inoculation with nematodes (200 per plant). Data were recorded 35 days after inoculation. 'Assist' = an interspecific hybrid, S. integrifolium x S. melongena; 'Companion' = an amphidiploid of S. integrifolium x S. melongena 'Uttara'; 'Compan- ion 2' =an amphidiploid of S. melongena 'Uttara' x S. integrifolium. mammosum (Fig. 1) in which the individual gall size was also bigger than those of the other sus- ceptible species. Experiment II In the graft combination of 'Senryo 2 gou'/S. sisymbriifolium, two to eight swellings per plant were observed; similar counts were obtained on non-grafted S. sisymbriifolium plants (Fig. 2). Im- munity and/or high resistance of S. torvum and S. toxicarium stocks against root-knot nematodes per- sisted even when top-grafted with scions from the susceptible eggplant. An average of one or less gall per plant was recorded in grafted or non- grafted plants of these two rootstock species inocu- lated with 1,300 nematodes per plant. Matsuzoe (unpublished data, 1990) grafted susceptible tomato Fig. 2. Number of galls present on 96- to 99-day-old non-grafted on the same rootstocks used in this experiment Solanum plants and those on plants grafted with scions of ' Senryo 2 gou' after inoculation with nematodes (1,300 per and obtained similar results, indicating that suscep- plant). Data were recorded 30 days after inoculation. tibility of the scion had no influence on nematode 'Companion' = an amphidiploid of S. integrifolium x S. melonge- resistance of wild Solanum species. This result na 'Uttara'. contradicts the result of Ishibashi and Shimizu (8) who reported nematode resistance of tomato (as (Fig. 2). In S. sisymbriifolium, 60 to 90% plants rootstock) is determined by both scion and stock. were invaded by nematodes forming small swell- 'Companion' and `Senryo 2 gou' were highly sus - ings in the roots. Total damage caused by primary ceptible whether grafted or not. invasion of nematodes and swelling of the roots is In S. torvum and S. toxicarium, 10 to 20% plants not known. Since nematodes form small giant cell were found infected (Table 1) by M incognita and the parasite can not survive (5), this species forming an average of one or less gall per plant can also be considered as resistant to some extent. 924 M. ALL N. MATSUZOE, H. OKUBO AND K. FUJIEDA

In all other genotypes 60 to 100% plants were investigation. Solanum sisymbriifolium, tolerant to found infected with nematodes resulting in profuse heat and cold, appears to be promising as stock root-galling. No gall was recorded in control seed- both for eggplant (M. Ali, unpublished data, 1989) lings or plants of S. khasianum. and tomato (11). This species is less resistant to It is evident that there is no resistance in egg- bacterial wilt than S. torvum and S. toxicarium plant against nematodes, and transfer of gene from (3, 12). Protoplast fusion between S. toxicarium and the wild resistant Solanum into eggplant may not S. sisymbriifolium or any other Solanum may be a be possible because of interspecific incompatibili- means to incorporate multiple disease, insect, and ty or hybrid sterility (1, 5, 13). All the somatic nematode resistance into regenerated progenies. hybrids between eggplant and S. khasianum, S. Such somatic hybrids resulting from protoplast fu- sisymbriifolium and S. torvum are also sterile sion might offer better plant with desirable root- (6, 17, 18). Direct use of these species as rootstock stock characteristics. However, it should be also faces commercial difficulty because of occa- remembered that in vitro regenerated somatic sional excessive vegetative growth of scion on S. hybrids, derived through phytohormones often lose torvum, and poor quality of eggplant fruits on S. their resistance to root-knot nematodes (5). The toxicarium (15) and its poor cold tolerance. Solanum present investigation has provided information for toxicarium is highly resistant to bacterial wilt, exploitation of persistent type of resistance of wild Fusarium wilt and Verticillium wilt as well Solanum to root-knot nematode through grafting, (3, 14, 19), and serves as a good rootstock for and the future scope for breeding resistant egg- tomato in summer season. Roots of S. toxicarium plant and tomato or their stock. contain a small amount of steroid alkaloid, toxic to Acknowledgement human (N. Nohara, personal communication, 1991). Translocation of this alkaloid into the scion graft- We are grateful to Dr. E. Kondo, Associate ed on S. toxicarium has not been investigated yet. Professor, Saga University for his identification of Therefore, use of this species as rootstock or the nematode species used as an inoculum. breeding material must be restricted until further

Table 1. Percentage of infected plants after 35 (seedlings) or 30 (grafted or non- grafted plants) days of nematode inoculation in Solanum genotypes. Values in parentheses are the results of second experiment. RESISTANCE OF NON-TUBEROUS SOLANUM TO ROOT-KNOT NEMATODE 925

Literature Cited London, New York. 1. Ali, M. and K. Fujieda. 1990. Cross compatibil- 11. Matsuzoe, N., M. Ali, H. Okubo and K. Fujieda. ity of eggplant (Solanum melongena L.) and wild 1990. Growth behavior of tomato plants grafted relatives. J. Japan. Soc. Hort. Sci. 58: 977-984. on wild relatives of Solanum melongena. J. Japan. 2. Ali, M., H. Okubo and K. Fujieda. 1990. In vitro Soc. Hort. Sci. 59 (Suppl. 2): 358-359. (In induced Solanum amphidiploid as rootstock of egg- Japanese). plant and tomato. J. Japan. Soc. Hort. Sci. 59 12. Matsuzoe, N., M. Ali, H. Okubo and K. Fujieda. (Suppl. 2) : 256-257. (In Japanese). 1991. Resistance of tomato grafted on Solanum 3. Ali, M., M. A. Quadir, H. Okubo and K. Fujieda. rootstocks to bacterial wilt. J. Japan. Soc. Hort. 1990. Resistance of eggplant, its wild relatives Sci. 60 (Suppl. 1) : 176-177. (In Japanese). and their hybrids to different strains of Pseudomo- 13. McCammon, K.R. and S. Honma. 1983. nas solanacearum. Scientia Hortic. 45 : 1-9. Morphological and cytological analysis of inter- 4. Fassuliotis, G. 1973. Susceptibility of eggplant, specific hybrid eggplant, Solanum melongena Solanun melongena, to root-knot nematode, x Solanum torvum. HortScience 18 : 894-895. Meloidogyne incognita. Plant Dis. Rep. 57 : 606-608. 14. Mochizuki, H. and K. Yamakawa. 1979. Resis- 5. Fassuliotis, G. and D. P. Bhatt. 1982. Potential of tance of selected eggplant cultivars and wild Sola- tissue culture for breeding root-knot nematode num species to bacterial wilt (Pseudomonas sola- resistance into vegetables. J. Nematol. 14 : 10-14. nacearum). Bull. Veg. Ornam. Crops Res. Stn. Ser. 6. Gleddie, S., W. A. Keller and G. Setterfield. A. No.6 : 1-10. (In Japanese with English 1986. Production and characterization of somat- summary). ic hybrids between Solanum melongena L. and S. 15. Mochizuki, H. and K. Yamakawa. 1979. sisymbriifolium Lam. Theor. Appl. Genet. Potential utilization of bacterial wilt resistant 71 : 613-621. Solanum species as rootstock for eggplant produc- 7. Hinata, K. 1986. Eggplant (Solanum melongena tion. Bull. Veg. Ornam. Crops Res. Stn. Ser. A. L.). p.363-370. In: Y. P. S. Bajaj (ed.). Biotechnol- No.6 : 11-18. (In Japanese with English summary). ogy in agriculture and forest, vol. 2, Crops I. 16. Purseglove, J. W. 1974. Tropical crops Springer-Verlag, Berlin, Heidelberg. dicotyledons. Longman, London. p.1-719. 8. Ishibashi, N. and K. Shimizu. 1970. Gall forma- 17. Sihachakr, D., R. Haicour, I. Serraf, E. Barrien- tion by root-knot nematode, Meloidogyne incognita tos, C. Herbreteau, G. Ducreux, L. Rossignol and (Kofoid et White, 1919) Chitwood, 1949, in the V. Souvannavong. 1988. Electrofusion for the grafted tomato plants, and accumulation of phos- production of somatic hybrid plants of Solanum phates on the gall tissues (Nematoda: Tylenchida). melongena L. and Solanum khasianum C.B. Clark. Appl. Ent. Zool. 5 : 105-111. Pl. Sci. 57: 215-223. 9. Jatala, P. 1981. Structure, organization and 18. Sihachakr, D., R. Haicour, M.-H. Chaput, E. Bar- methodology of international trials for root-knot rientos, G. Ducreux and L. Rossignol. nematode (Meloidogyne sp.) resistant material. 1989. Somatic hybrid plant produced by electro- p.127-132. In: Development in the control of fusion between Solanum melongena L. and Sola- nematode pests of potato. Rep. 2nd Nematol. Plan. num torvum SW. Theor. Appl. Genet. 77: 1-6. Conf. 1978. CIP, Lima, Peru. 19. Yamakawa, K. and H. Mochizuki. 1978. Studies 10. Khan, R. 1979. Solanum melongena and its an- on the use of disease resistance of wild non- cestral forms. p.629-636. In: J. G. Hawkes, R. N. tuberous Solanum species in the breeding of egg- Lester and A. D. Skelding (eds.). The biology and plants. Abstract No. 1676, 20th Int. Cong. Hortic. taxonomy of the Solanaceae. Academic Press, Meeting, Sydney, Australia. 926 M. ALI, N. MATSUZOE, H. OKUBO AND K. FUJIEDA

非 塊 茎性 ナ ス属 植 物 の ネ コブ セ ンチ ュ ウ抵 抗性

モハ メ ド ア リ ・松 添直隆*・ 大 久保 敬 ・藤枝 國光

九州大学農学部 812 福岡市東区箱崎

摘 要

ナ ス とそ の近 縁 野 生 種,種 間 雑 種 お よ び 複 二 倍 体 の 卵 形 成 に は 至 ら な か っ た.こ れ ら を 台 木 と した 接 ぎ木 ネ コブ セ ン チ ュ ウ(Meloidogyne incognita)に 対 す る 植 物 は 穂 木(非 抵 抗 性 ナ ス)の 影 響 を受 け ず,同 様 な 抵 抗 性 を,実 生 苗 お よ び 非 抵 抗 性 ナ ス を穂 木 と した接 抵 抗 性 を 示 した.一 方,ナ ス,S. integrifolium,両 者 の ぎ木 植 物 に 接 種 して 評 価 した.Solanum khasianum, S. 種 間雑 種 と そ の 複 二 倍 体,お よ びS. indicumに は 抵 抗 お よ びS. toxicariumでtorvumは 強 度 の 抵 抗 性 が 観 察 性 が 認 め ら れ ず,ま たS. mammosumとS. surattense さ れ た.S. sisymbriifoliumで は セ ン チ ュ ウ の 侵 入 で根 は ネ コブ セ ン チ ュ ウ に 特 に 弱 い こ とが 確 か め られ た. に小 さ な 膨 らみ を 生 じた が,セ ン チ ュ ウ は 成 熟せ ず,

*現 在:鹿 児 島 大学 農 学部890鹿 児 島市郡 元