Heterosis studies in tomato (Lycopersicon esculentum Mill.) hybrids for root and biochemical characters for root knot nematode resistance

Advances in Environmental Biology, 3(): 0-4, 009 ISSN 995-0756 009, American-Eurasian Network for Scientific Information 0 This is a refereed journal and all articles are professionally screened and reviewed ORIGINAL ARTICLE Heterosis studies in tomato (Lycopersicon esculentum Mill.) hybrids for root and biochemical characters for root knot nematode resistance C. Indu Rani, D. Veerargavathatham and M. Prabhu Horticultural college and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India 64 003 C. Indu Rani, D. Veerargavathatham and M. Prabhu, Heterosis studies in tomato (Lycopersicon esculentum Mill.) hybrids for root and biochemical characters for root knot nematode resistance, Adv. Environ. Biol., 3(): 0-4, 009 ABSTRACT The present investigation was undertaken to study the heterosis for root and biochemical components in tomato using twenty three hybrids which are highly resistant to root knot nematode (Meloidogyne incognita) involving eleven parents in Line x Tester fashion. It is possible to exploit hybrid vigour through heterosis breeding considering the behaviour of traits like length of roots, weight of roots and biochemical parameters loke total phenols, ortho dihydroxy phenol, IAA oxidase, Chlorogenic acid, Ascorbic acid in roots are the two most important resistance attributing traits. Heterosis was appreciable in all the twenty three hybrids, but it was more in the four hybrids viz., CLN 06C x SL 0, CLN 06E x SL 0, LE 8 x SL 0 and CLN 464A x SL 0. These crosses can be selected for the exploitation of hybrid vigour and commercial utilization under root knot nematode infested areas. Key words: Heterosis, Tomato, Root knot nematode resistance Introduction Tomato (Lycopersicon esculentum Mill.) is one of the most economically important vegetables in Asia. The fruits are consumed raw, cooked or processed as juice, ketchup, sauce, paste, puree etc. It is a good source of Vitamin C, Vitamin A and Vitamin B. Tomato plants have been reported to be severely affected by several plant parasitic nematodes, especially by the root knot nematodes, Meloidgyne spp. The yield loss in tomato due to root knot nematodes has been estimated to be upto 6 per cent[3]. Identification of nematode resistant donors and utilization in development of F hybrids by hybridization with high yielding lines will be a boon to tomato growers for maximum production of quality tomatoes without much residue of chemicals through the use of nematicides. Resistance to root knot nematode in tomato was found sixty years ago in Lycopersicon peruvianum accession PI 8657 by Bailey []. The resistance was transferred and expressed in F hybrid derived from L. peruvianum x L. esculentum crosses[5]. An appreciable improvement in yield coupled with a considerable level of resistance can be achieved through the development of F hybrids. The resistant varieties possess various biochemical barriers to restrict growth of the nematode in the host cell. Hence the knowledge of sources of resistance and their biochemical background is an important pre requisite. A programme to combine good yield with root knot nematode resistance thus assumes great importance. In the light of above, an attempt was therefore made to estimate the magnitude of heterosis for yield, root characters and biochemical parameters in root knot nematode (Meloidogyne incognita) resistant hybrids. Corresponding Author M. Prabhu, Horticultural college and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India 64 003 Email: muprabhu000@yahoo.com

Adv. Environ. Biol., 3(): 0-4, 009 Materials and methods The present study was carried out at the College Orchard, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore. In the present investigation, eighty hybrids and their fourteen parents were evaluated in a Line x Tester fashion and based on the per se performance, twenty three hybrids were found to be highly resistant to root knot nematode. These twenty three hybrids along with their eleven parents were selected and raised during June October 00 in a randomized block design with three replications. Twenty five plants were maintained in each replication. Thirty days old seedlings were planted at a spacing of 60 x 45 cm. All recommended package of practices were followed. Observations were recorded on root length, root weight, total phenols, ortho dihydroxy phenols, IAA oxidase, Chlorogenic acid, Ascorbic acid in roots and yield per plant. Statistical analysis was done on the mean values and the heterosis was determined as the increase or decrease in F hybrids over the mid and best parents. Results and discussion The mean performance of parents and crosses are presented in Table. The per cent of heterosis estimated over mid and best parent for yield and other characters are given in Tables,3,4,5 and 5. The evaluation of the parents and resistant hybrids was accomplished based on their per se performance and heterosis. With respect to yield per plant, the parent LE 8 recorded the highest yield followed by CO 3. Most of the hybrids recorded significant and positive heterosis estimates over their respective mid parental values. Heterosis, for yield was reported by Aruna[] and Sankari[4]. Significant heterosis over the best parent was observed in CLN 06E x SL 0 and LE 8 x SL 0. These hybrids involved high x high and medium x high per se parental combinations. Williams[6] suggested that heterosis for yield was the consequence of multiplicative relationship between the component characters of the yield complex. It may sometime be due to modifying factors in the reflection of these component traits to yield. Root length is one of the root knot nematode resistant traits. The highest root length was recorded in the parent SL 0. Among the hybrids, CLN 06E x SL 0, LE 8 x SL 0, CLN 464 A x SL 0 and CLN 06C x SL 0 recorded high mean performance for root length and these four hybrids only showed positive significant heterosis over the best parent. The fresh root weight was considered as an important root knot nematode resistant trait. The galled roots recorded more root weight than the resistant roots of tomato plants. In the present study, the mean performance of parents showed superiority of PT 476A,, SL 0, Patriot, and LE 8 by recording lesser root weight. All hybrids, which involved these parents also, expressed lowest mean performance. All the hybrids expressed negative heterosis over the best parent except, CLN 06C x Patriot, CLN 06C x SL 0, CLN 06E x SL 0, CLN 464A x SL 0, PT 467 A x, PT 467A x Patriot, PT 476A x SL 0 and LE 8 x. The total phenol content among the parents was highest in SL 0 and LE 8. Among the hybrids CLN 06E x SL 0, LE 8 x SL 0, x CLN 464A, CLN 464A x, CLN 06C x Patriot, LE 8 x Patriot and CLN 06C x SL 0 exhibited higher values for this trait. These seven hybrids exhibited significant positive heterosis over the best parent. The hybrid mean was higher than the parental mean implying more degree of resistance in hybrids than parents. The nematode infestation is hampered by special biochemical mechanism involving compounds like phenols. Heterosis for phenol content to show resistance against TLCV was reported by Sankari[4]. With respect to orthodihydroxy phenol content, the parents SL 0 and LE 8 recorded highest per se for this trait. The hybrids, LE 8 x SL 0, CLN 464A x and x CLN 464 A recorded highest mean performance and only these three hybrids showed significant positive heterosis over the best parent. The parental mean was lesser than that of the hybrid mean. Similar finding was reported by Sankari[4] in respect of TLCV resistant F hybrids. The highest IAA oxidase activity, which is one of the important root knot nematode resistant traits, was recorded by the parents, SL 0, LE 8 and. Among the hybrids, CLN 06C x SL 0 recorded the highest IAA oxidase activity closely followed by Patriot x PT 476A. These two hybrids exhibited highest positive heterosis over the best parent. The hybrid mean exceeded the parental mean by showing more IAA oxidase activity. With respect to chlorogenic acid content, the parents SL 0, Patriot and LE 8 recorded highest per se performance. The hybrid CLN 06E x SL 0 recorded the high chlorogenic acid content. All the hybrids recorded significant positive heterosis over the best parent except, CLN 06C x Patriot, CLN 464A x, CLN 464A x SL 0, PT 467A x, PT 467A x Patriot, PT 467A x SL 0 and x LE 8. The hybrid mean is twice that of the parental mean suggesting the better synthesis or availability of this chemical to resist nematode infestation.

Adv. Environ. Biol., 3(): 0-4, 009 Table : Per se performance of parents and resistant hybrids under field condition Genotypes Yield per Root Root Ascorbic Total Ortho IAA Chlorogenic plant (kg) length (cm) Weight (g) acid in roots phenol dihydroxy oxidase acid (mg/g) (mg/00g) (mg/g) phenol (mg/ (mg/g) 00mg) CLN 06C.6.75.30 3.7 40.75 4.3 8.83 3.0 CLN 06E.73 5.68 3.53 8.4 3.54.5 30.38 30.30 CLN 464A.0 7.67 9.50 9. 3.33 8.97 4.73.80 PT 467A 0.93 4.37.85 0.03 8.58.47 40.50.7 PT 476A. 6.73 3.0 49.93 9.58 33.80 7.00 7.45 CO 3.0 30. 4.37 30.57 4.73 8.90 53.97 3.0 LE 8.7 7.83 5.93 4.80 4.57 5.48 79.00 75.30 0.73 5.38 4. 48.47 0.75 4.98 7.00 60.97.47 7.00 5.57 57.40 06.48 49.58 74.97 66.0 Patriot.0 5.77 5.55 6.37 03.58 5.0 70.8 79.57 SL 0.77 30.88 5.00 63.7 3.4 66.7 80.0 8.45 Mean.5 4.03 7.35 4.0 75. 36.39 56.85 5. CLN 06C.70 6.4.47 6.47.75 56. 5.00 85.0 CLN 06C Patriot.95 5.30 7.63 49.50 4.80 50.73 49.50 84.67 CLN 06C SL 0.45 35.48 3.83 68.40 48.7 65.57 8.33 8.8 CLN 06E SL 0.34 3.85 5.03 67.70 36.48 63.70 8.00 79.0 CLN 464A.37.5.6 40.37 43.7 73.53 76.40 58.30 CLN 464A SL 0.4 34.76 4.77 64.9 3.0 60.89 00.75 64.07 PT 467A.46 8.7 4.47 6.67 4.0 50.86 5.3 7.5 PT 467A Patriot.46 6.87 6.67 6.75 3.43 40.4 5.33 80.5 PT 467A SL 0.3 3.0 0.57 68.53 3.80 43.38 7.58 8.43 PT 476A SL 0..98 5.35 40.89 5.73 65.53 5.05 0.80 CO 3.79 3.9.78 60.63 8.85 66.37 5.40 08.83 CO 3 Patriot.30 7.47 9.88 65.67 3.7 56.07 4.00 68.40 CO 3 SL 0. 7.58 0.8 63.0 3.60 65.40 86.45 69.30 LE 8.85.33 3.37 6.30 3.7 5.00 4.3 57.75 LE 8.44 30.50.77 6.30 3.33 66.38 39.00 7.63 LE 8 Patriot.3 3.87 9.3 6.43 40.8 60.83 44.07 49.30 LE 8 SL 0.37 35.33.98 66.40 46.30 75.37 44.00 50.07 CLN 464A.05 9.60 0.73 4.07 43.6 70.43 59.67 9.38 PT 476A 0.85 8.8.40 46.60.0 5.7 83.3 0.7 LE 8.06 6.9.63 5.30 06.7 4.3 69.8 7.76 Patriot PT476A 0.96 4.80.47 38.3 0.40 63.7 8.07 09.53 Patriot LE 8.4 0. 0.7 38.57 30.83 50.98 7.7.86 SL 0 CLN 464A.77 9.3.7 46.07 00.90 40.95 40.5 0.8 Mean.63 7.58.65 53.36 5.35 57.83 68.54 7.7 CD(0.05) 0.9.740.536.53 3.605 3.705.579.7 Table : Heterosis per cent for yield per plant Hybrids di dii diii CLN06C x 45.9** 5.59 -.65** CLN 06C x Patriot 48.85**.** -0.3* CLN 06C x SL 0 40.00** 38.4**.90* CLN 06E x SL 0 38.46** 3.0** 7.83 CLN 464A x -.6** -3.84** -36.87** CLN 464A x SL 0 8.5** 6.55** 3. PT 467 A x.67** -0.68-3.7** PT 467A x Patriot 50.5** 44.56** -3.7** PT 467A x SL 0 -.96-5.98** -39.63** PT 476A x SL 0-4.83** -36.7** -48.38** CO 3 x 6.05** -4.76** -7.5** CO 3 x Patriot 47.43** 9.5 5.99 CO 3 x SL 0-37.6** -4.38** -44.3** LE 8 x 7.58** -4.75** -4.75** LE 8 x -0.88** -33.64** -33.64** LE 8 x Patriot 40.5**.77.77 LE 8 x SL 0-0.30** 9. 9.** x CLN 464A -39.65** -47.76** -5.6** x PT 476A -36.56** -4.7** -60.8** x LE 8-4.75** -5.5** -5.5** Patriot x PT 476A -3.5-0.66* -55.76** Patriot x LE 8 -.0** -4.85** -4.85** SL 0 x CLN464A -6.34 -.94* -8.43`** * Significant at 5 per cent level ** Significant at per cent level

Adv. Environ. Biol., 3(): 0-4, 009 3 Table 3: Heterosis per cent for root length and root weight Hybrids Root length Root weight ----------------------------------------------------------- -------------------------------------------------- CLN06C x 38.54** 4.09-4.44** -9.78** -.30* -4.8 CLN 06C x Patriot 3.36** -.8-8.07** -4.34-3.38** 34.58** CLN 06C x SL 0 5.40** 4.89** 4.89** -3.80** -7.80 5.57 CLN 06E x SL 0 50.55** 6.38** 6.38* -.00** 0.0 4.73** CLN 464A x -5.3 -.67** -3.5** -8.05** -8.95** -3.66 CLN 464A x SL 0 43.6**.57**.57** -4.38** -.53.75* PT 467 A x 9.65** 4.33-8.78** -4.67** -7.06 0.45 PT 467A x Patriot 7.8* 4.6 -.99** -3.7** 7.0 7.5** PT 467A x SL 0-6.39** -5.9** -5.9** -44.6** -9.53** -9.3** PT 476A x SL 0-0.3** -5.58** -5.58** 9.5 7.7** 7.7** CO 3 x -3.96** -0.8** -.54** -7.6** -7.5** -0.07 CO 3 x Patriot -.86-9.06** -.04** -33.95** -3.5** -4.58** CO 3 x SL 0-9.7** -0.69** -0.69** -6.34** -4.70** -7.40** LE 8 x -6.08** -9.76** -7.68** -.33* -5.98.06 LE 8 x.3** 9.59** -.3-8.9** -7.98** -.5 LE 8 x Patriot 8.9** 4.5** 3. -4.36** -40.64** -9.54** LE 8 x SL 0 0.33** 4.4** 4.4** -.55** -0.3** -8.55 x CLN 464A 3.50** 9.6** -4.4-38.8** -3.08** -8.09** x PT 476A 5.4 4.74-8.4** -0.50** -.97* -.97* x LE 8-4. -5.53-4.86** -9.80** -8.88** -3.58 Patriot x PT 476A -5.5-7.* -9.69** -9.95** -.44* -.44* Patriot x LE 8-4.55** -7.34** -34.5** -34.75** -33.95** -.60** SL 0 x CLN464A 9.97** -5.67* -5.67* -34.68** -7.5** -3.96* * Significant at 5 per cent level ** Significant at per cent level Table 4: Heterosis per cent for total phenol and orthodihydroxy phenol Hybrids Total phenol 0rthodihydroxy phenol ----------------------------------------------------------- -------------------------------------------------- CLN 06C x 69.68** 8.49** -8.05** 70.06** 33.9** -5.73** CLN 06C x Patriot 96.48** 36.90** 7.08** 34.67** -0.9-3.96** CLN 06C x SL 0 80.86**.96**.96** 44.0** -.7 -.7 CLN 06E x SL 0 57.6** 3.06* 3.06* 44.97** -4.5-4.5 CLN 464A x 07.9** 34.55** 8.9** 4.49** 48.30** 0.0** CLN 464A x SL 0 60.** -0.99-0.99 4.0** -8.73** -8.73** PT 467 A x 83.77** 6.55** -6.8** 63.9**.58-3.77** PT 467A x Patriot 7.65** 9.5** -4.34** 8.64** -.05** -39.4** PT 467A x SL 0 4.37** -4.06** -4.06** 9.55* -34.98** -34.98** PT 476A x SL 0.76** -5.05** -5.05** 30.38** -.78 -.78 CO 3 x 78.36** 5.40** -.70 87.7** 58.09** -0.5 CO 3 x Patriot 8.03** 7.69** -0. 40.00** 9.5* -5.96** CO 3 x SL 0 5.7** 0.3 0.3 36.79** -.97 -.97 LE 8 x 3.35** 7.50** -6.98** 9.3** -0.93-3.56** LE 8 x 8.8** 4.6** -0.8 3.36** 8.94** -0.5 LE 8 x Patriot 9.0**.9** 6.34** 8.48** 8.6** -8.83** LE 8 x SL 0 8.46** 0.48** 0.48** 7.53**.96**.96** x CLN 464A 08.4** 34.88** 8.46** 05.46** 4.05** 5.56* x PT 476A.6** 4.33* -6.0**.98** 3.40-3.5** x LE 8-3.85** -7.4* -9.75** -8.60** -0.0** -38.35** Patriot x PT 476A 3.38* -.0-3.4** 48.88** 3.57** -5.7 Patriot x LE 8 9.94** 4.9** -.0-0.70-0.97-3.59** SL 0 x CLN464A 3.** -3.80** -3.80** -4.43-38.6** -38.6** * Significant at 5 per cent level ** Significant at per cent level Regarding ascorbic acid in roots, the parents SL 0 and Patriot recorded the highest per se. The hybrid PT 467A x SL 0 recorded the highest ascorbic acid in roots in both per se and positive significant heterosis over the best parent. Only four hybrids showed significant positive heterosis over the best parent. Heterosis was appreciable in all the twenty three hybrids, but it was more in the four hybrids viz., CLN 06C x SL 0, CLN 06E x SL 0, LE 8 x SL 0 and CLN 464A x SL 0. These four hybrids have to be further studied for their stability in yield and quality traits under different locations.

Adv. Environ. Biol., 3(): 0-4, 009 4 Table 5: Heterosis per cent for IAA oxidase and chlorogenic acid Hybrids IAA oxidase Chlorogenic acid ------------------------------------------------------------ --------------------------------------------------- CLN06C x.6-8.7** -36.3** 84.83** 39.58** 3.** CLN 06C x Patriot -0.66-30.0** -38.0** 5.6** 6.40** -.69* CLN 06C x SL 0 6.63** 47.3** 47.3**.49** 0.5** 0.5** CLN 06E x SL 0 4.** -47.7** -47.7** 5.4** 7.** 7.** CLN 464A x 53.5**.90-4.6** 3.65** -.80** -9.9** CLN 464A x SL 0 9.9** 5.7**8 5.78** 3.4** -.9** -.9** PT 467 A x 9.54** -30.33** -34.79** 6.85** 8.0** -3.5** PT 467A x Patriot -7.77** -7.5** -35.9** 57.60** 0.85 -.66* PT 467A x SL 0-8.7** -0.63** -0.63** 55.** -.3 -.3 PT 476A x SL 0-8.65** -36.7** -36.7** 43.98** 34.38** 34.38** CO 3 x -6.4** -6.9** -34.58** 33.84** 78.49** 3.99** CO 3 x Patriot -34.9** -4.0** -48.8** 0.57**.63** 04.5** CO 3 x SL 0 8.95** 7.9** 7.9** 95.56** 05.34** 05.34** LE 8 x -45.03** -47.8** -48.5** 3.5** 09.49** 9.3** LE 8 x -49.34** -50.63** -5.3** 4.75** 7.9** 08.6** LE 8 x Patriot -4.6** -44.** -44.98** 9.79** 87.63** 8.08** LE 8 x SL 0-44.69** -45.06** -45.06** 90.5** 8.0** 8.0** x CLN 464A -9.69** -0.40** -5.5** 07.78** 38.5** 0.83** x PT 476A 4.0**.0** 3.90** 74.7** 68.8** 45.79** x LE 8-9.3** -.6** -.83**.49-4.70** -.96** Patriot x PT 476A 66.7** 66.9** 47.40** 45.05** 37.65** 3.84** Patriot x LE 8 56.4** 48.3** 46.7** 44.44** 40.58** 35.67** SL 0 x CLN464A -3.40** -49.87** -49.87** 30.73** 45.88** 45.88** * Significant at 5 per cent level ** Significant at per cent level Table 6: Heterosis per cent for ascorbic acid in roots Hybrids di dii diii CLN06C x 5.6** 6.8** -3.53 CLN 06C x Patriot 5.7* -9.34** -.3** CLN 06C x SL 0 4.50** 7.34** 7.34** CLN 06E x SL 0 46.95** 6.4** 6.4** CLN 464A x -6.68* -9.67** -36.65** CLN 464A x SL 0 39.85**.88.88 PT 467 A x -59.7** 7.44** -3. PT 467A x Patriot 54.8**.5 -.5 PT 467A x SL 0 63.63** 7.54** 7.54** PT 476A x SL 0-8.05** -35.8** -35.8** CO 3 x 53.4** 5.08** -4.85* CO 3 x Patriot 4.63** 6.84**.90 CO 3 x SL 0 33.8** -0.97-0.97 LE 8 x 38.0** 8.53** -.3 LE 8 x 5.60** 8.53** -.3 LE 8 x Patriot 9.07** 0.0-3.59 LE 8 x SL 0 5.85** 4.0* 4.0* x CLN 464A -5.06* -8.45** -35.55** x PT 476A -3.7** -8.8** -6.87** x LE 8 3.4-0.6** -9.49** Patriot x PT 476A -3.48** -37.86** -40.6** Patriot x LE 8-5.4** -37.5** -39.47** SL 0 x CLN464A -0.75-7.69** -7.69** * Significant at 5 per cent level ** Significant at per cent level References. Aruna, S., 99. Studies on the performance of certain F hybrids in tomato (Lycopersicon esculentum Mill.), M.Sc. Thesis, Tamil Nadu Agricultural University, Coimbatore.. Bailey, D.M., 94. The seedling test method for root-knot nematode resistance. Proc. Amer. Soc. Hort. Sci., 38: 573-575. 3. Nirmaladevi, S. and S.K. Tikoo, 99. Studies of the reaction of certain tomato genotypes and their F to combined infection by Meloidogyne incognita and Pseudomnas solanaceaum. Indian J. Genetics and Pl. Breeding, 5: 8-5. 4. Sankari, A., 000. Studies on the development of F hybrids is tomato (Lycopersicon esculentum Mill.) with high yield and resistance to tomato leaf curl virus. Ph.D. Thesis, Tamil Nadu Agricultural University, Coimbatore. 5. Smith, P.G., 944. Embryo culture of a tomato species hybrid. Proc. Amer. Soc. Hort. Sci., 44: 43-46. 6. Williams, W., 959. Heterosis and genetics of complex characters. Nature, 84: 58-550.