Current Advances in Agricultural Sciences 3(1): 54-56 (June 2011)
ISSN 0975-2315
SHORT COMMUNICATION
Heterosis and inbreeding depression in sesame (Sesamum indicum L.) KB GAIKWAD* and JP LAL Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221 005 (Uttar Pradesh), India *Email of corresponding author:
[email protected] Received: August 2009; Accepted: March 2010 Key words: Heterosis, Inbreeding depression, Seed yield, Sesame
Sesame (Sesamum indicum L.) is an important annual oilseed crop in the tropics and warm subtropics. India ranks first in the world in sesame cultivation (29% area) but its productivity is low (413 kg ha-1) as compared to that of Asia (493 kg ha-1) and the world (464 kg ha-1) (FAO, 2008). Sesame is pre-dominantly a self-pollinated crop and the scope of hybrid vigour depends on the direction and magnitude of heterosis. The success of developing commercial hybrids depends upon the choice of superior parents for high expression of heterosis by spotting the potentiality of good hybrid combinations. Hybrid technology has been widely acclaimed as a modern approach for the genetic improvement of yield in various crop species including sesame. However, the advantage of hybrid vigour is not so been exploited commercially, rather it is used to isolate a higher frequency of productive derivatives in their later generations. Inbreeding is the basic mechanism for providing the base material for selection. The nature and magnitude of inbreeding depression helps to the efficiency of selection. The present investigation was carried out to study the heterosis in F1 over better parent, mid parent, standard parent and inbreeding depression over F 2 segregating generation for seed yield and its related traits in sesame. The experiment was conducted during the rainy season of 2004 and 2005 at Agriculture Research Farm of the Institute of Agricultural Sciences, Banaras Hindu University, Varanasi. The experimental material comprised of ten crosses in sesame, viz. GT 1 X Shekhar, GT 1 x TC 289, GT 1 x JLT 8, GT 1 x ES 3, GT 1 x T 12, JLT 8 x T 12, JLT 8 x ES 3, JLT 8 x TC 25, JLT 8 x TC 289 and JLT 8 x T 4. Six generations of these crosses, viz. P1, P2, F1, F2, B1 and B2 were grown in randomized block design with three replications during kharif 2005-06. Seeds of each cross and their generations were sown in a row of 4 m length in each replication with a spacing of 45 cm between the rows and 15 cm between plants. Observations on different yield attributing traits namely, days to 50% flowering, days to maturity, plant height, length of main axis, number of primary branches, number of capsules on main axis, number of capsules plant-1, length of
capsule, number of seeds capsule-1, 1000-seed weight and yield plant-1 were recorded on 10 plants each in P1, P2 and F1, 40 plants in F2 and 20 plants each in B1 and B2. Relative heterosis, heterobeltiosis and standard heterosis were estimated following the methods suggested by Hays et al. (1955). Variety ‘TC 25’ was used as standard check. Inbreeding depression was estimated by the method suggested by Kempthorne (1957). The nature and magnitude of heterosis revealed that most of the hybrids exhibited significant and negative relative heterosis and heterobeltiosis for days to 50% flowering (Table 1). Maximum negative heterosis over better parent (-9.27%) was observed in the cross GT 1 x Shekhar. Early maturing hybrids are desirable in sesame to fit well in the multiple cropping systems. Significant negative heterosis for earliness was earlier reported by Kumaresan and Nadarajan (2004). Out of ten hybrids, six hybrids exhibited significant and negative heterosis for days to maturity over mid, better and standard parent. Hybrids GT 1 x Shekhar and JLT 8 x TC 25 recorded highest negative heterosis over better parent (-9.32%) and standard parent (-5.28%), respectively. Duhoon (2004) has also reported negative standard heterosis for the trait. In case of plant height, all the hybrids except GT 1 x TC 289 and GT 1 x ES 3 exhibited significantly shorter plant height as compared to standard check. Cross JLT 8 x T 12 reported high negative heterosis (-10.41%) over standard parent. Dwarf stature is preferable as it is less prone to lodging. The results are similar to those obtained by Reddy et al. (2001). The extent of standard heterosis for number of primary branches ranged from 11.22% to 24.66%. Except hybrid GT 1 x ES 3, almost all the crosses showed significant standard heterosis for this trait. Number of capsules on main axis is generally associated with higher yield. All the hybrids except GT 1 x Shekher and GT 1 x JLT 8 showed significant standard heterosis. Hybrid GT 1 x ES 3 recorded highest standard heterosis (59.58%) for this trait. Number of capsules plant-1 is one of the most important yield component. Thus, the hybrids with positive heterosis are
*Present Address: Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana-141 004 (Punjab), India
GAIKWAD AND LAL – HETEROSIS AND INBREEDING DEPRESSION IN SESAME (Sesamum Indicum L.)
55
Table 1. Heterosis (%) over mid parent (H1), better parent (H2), standard variety ‘TC 25’ (H3) and estimates of inbreeding depression for eleven traits in sesame
Crosses
GT 1 x Shekher
GT 1 x TC 289
Heterosis Days to over 50% flowering H1 -4.85** H2 -9.27** H3 -2.14 ID -16.04
Length of Primary Capsules Capsules Length Seeds 1000-seed Yield main axis branches on main plant-1 of capsule-1 weight plant-1 axis capsule -3.99** -3.08** 0.65 15.96** 16.84** 7.30** 6.00** 11.46** 6.11** 26.17** -9.32** -6.91** -2.49** 2.78 8.71** 3.71* 3.51* 6.42** 3.24* 13.73** -4.53** -5.12** -0.32 13.78** 3.70 8.25** 5.74** 6.32** 10.33** 27.17** -2.77** 6.26** 3.40** -2.25* 11.56** 4.90** 3.68 4.05** 2.35** 10.97**
Days to Plant maturity height
H1 H2 H3 ID H1 H2 H3 ID
-1.64 -9.09** 7.14* -3.34 -3.14** -0.72 -0.71 -2.89
0.00 -6.51** 3.02** -1.83 -3.08** -0.79** -4.91** -5.95**
-2.42** -4.39** 0.70 3.27** -3.97** -5.39** -3.45** 7.95**
-1.68** -3.07** 1.97** 4.78** -1.01* -2.72** -0.55 8.58**
15.83** 10.14** 24.66** 8.86** 14.50** 11.16** 13.44** 14.93**
17.79** 9.68** 3.82** 12.29** 7.65** 0.89 18.13** 16.69** 9.01** 13.69** 8.39** 5.76** 13.78** 7.15** 6.30** 8.35** 3.64** 3.81* 3.35 8.17** 6.01** 15.62** 5.26** -1.12
GT 1 x ES 3
H1 H2 H3 ID
-4.47** -7.95** -0.71 -5.05**
-4.71** -2.13** -8.66** -3.08** -4.53** -0.11 -5.92** 4.22**
-2.70** -7.33** 4.69** 4.35**
3.46 -3.36 -1.37 5.46**
27.61** 7.83** 7.12** 7.26** 5.25** 22.19** 3.13 2.94* 0.80 2.81* 2.78 14.26** 59.58** 18.16** 16.50** 12.01** 10.02** 45.99** 18.31** 7.59** 1.54 1.35* 4.46** 12.83**
GT 1 x T 12
H1 H2 H3 ID
-2.46* -4.14** -0.71 -4.31**
-1.94** 0.11 -3.44** -5.11** -4.53** -4.09** -4.74** 6.50**
0.51 -2.75** -0.58 2.50*
2.45 -1.59 0.43 -3.32
JLT 8 x T 12
H1 H2 H3 ID
-6.16** -6.80** -2.14 -3.63**
-2.65** -1.62** -0.49 -3.38** -2.19** -0.95 -3.02** -10.41** -5.30** -3.10** 0.78 -0.30
JLT 8 x ES 3
H1 H2 H3 ID
-4.03** -3.50** 0.42 -5.30** -5.42** -5.17** 2.14 -1.13 -2.26** -5.58** -6.49** 8.74**
JLT 8 x TC 25
H1 H2 H3 ID
-5.23** -7.48** -2.86 -3.68**
JLT 8 x TC 289
JLT 8 x T 4
GT 1 x JLT 8
CD (P=0.05) CD (P=0.01) CD (P=0.05) CD (P=0.01)
4.33** 1.59 7.13** 7.27** 7.32** 6.03** 5.93** 4.91**
3.36* 1.56 8.71** 5.58** 5.89** 1.89 8.91** 5.03**
18.65** 15.10** 36.13** 19.85** 21.37** 11.78** 24.99** 14.44**
9.59** 7.25** 7.26** -2.54 2.40* 7.10** 19.40** 17.51** 9.51** 15.08** 11.07** 5.46**
6.62** 5.64** 7.51** 2.13**
6.99** 5.30** 12.72** 5.38
24.62** 22.01** 8.81** 9.73** 20.31** 3.96 0.64 7.00** 13.10** 27.37** 15.49** 9.41** 11.03** 8.70** 0.77 5.46**
7.56** 5.31** 7.18** -1.20
3.78** 21.03** 1.37 7.56** 5.08** 30.26** 1.37* 0.92
1.15 -7.01** 5.04** 4.36**
20.37** 30.23** 16.20** 12.18** 19.61** 1.42 7.46** 3.24* 5.99 56.93** 23.35** 19.33** 5.58** 18.91** 11.11** 9.27**
9.34** 10.01** 38.85** 3.60** 8.30** 20.57** 12.87** 10.48** 54.05** -1.78** 3.40 19.11**
-5.46** -5.65** -5.64** -9.62** -5.28** -9.62** -4.37** 1.04
-3.01** -5.56** -5.56** -0.54
18.63** 16.18** 11.22** 8.20** 11.22** 8.20** 9.46** 5.85
7.93** 6.40** 6.40** 2.52
4.65** 3.35** 3.35** 1.66
4.24** 18.42** 3.64* 14.95** 3.64* 14.95** 4.45** 8.86**
H1 H2 H3 ID
-0.64 -0.36 -1.69** -6.06** -4.79** -8.10** 10.71** 4.91** -3.20** -1.93* -4.31** 0.70
-1.20 -6.12** -1.23 0.58
23.29** 16.41** 11.04** 10.24** 9.30** 5.93* 5.47** 4.69** 23.72** 11.43** 14.33** 13.12** 8.92** 8.29** 8.53** 12.43**
9.85** 5.72** 11.48** 6.69**
7.62** 5.30** 8.79** 3.72*
30.81** 17.46** 38.92** 18.03**
H1 H2 H3 ID
-4.03** -3.12** -2.80** -5.30** -5.38** -4.41** 2.14 -0.38 -9.45** -4.88** -1.89* -1.89*
-2.51** -2.94** -7.24** -1.95*
15.45** 11.58** 9.18** 6.17** 4.43 1.09 2.77* 4.67** 12.93** 7.39** 13.56** 4.67** 10.22** 9.67** 6.61** 5.71**
6.94** 6.08** 5.12** 2.02**
1.37 -0.65 2.28 -1.12
18.74** 9.34** 22.29** 8.68**
1.43 1.96 1.65 2.27
0.09 0.12 0.10 0.14
0.88 1.21 1.02 1.40
H1 H1 H2 & H3 H2 & H3
1.01 1.39 1.17 1.60
1.15 1.58 1.33 1.83
*, ** Significant at 5% and 1%, respectively;
1.24 1.71 1.44 1.97
1.25 1.72 1.45 1.98
0.23 0.32 0.27 0.37
1.23 1.69 1.42 1.95
8.55** 7.20** 7.20** 3.07*
1.85 2.54 2.14 2.94
0.09 0.12 0.10 0.14
22.75** 17.73** 42.58** 17.60**
ID = Inbreeding depression
desirable for higher yields. Hybrids, JLT 8 x ES 3 (23.35%), GT 1 x ES 3 (18.16%) and GT 1 x T 12 (17.51%) showed positive and significant heterosis over standard variety for this trait. A similar result was reported by Ragiba and Reddy (2000). Length of
capsule and number of seeds capsule-1 are the two important yield contributing traits. All the hybrids exhibited significant and positive standard heterosis for these traits. Hybrid JLT 8 x ES 3 showed higher standard heterosis for length of capsule
56
CURRENT ADVANCES IN AGRICULTURAL SCIENCES 3(1): JUNE 2011
(19.33%) and for number of seeds capsule-1 (12.87%). These findings are in close agreement with those of Reddy et al. (2001). The extent of standard heterosis for 1000-seed weight ranged from 3.46% to 12.72%. Estimates of standard heterosis for this trait were significant and positive in all the ten crosses. Hybrids GT 1 x T 12 (12.72%), JLT 8 x ES 3 (10.48%) and GT 1 x Shekher (10.33%) were found to be the best hybrids. Heterosis for the end product i.e., seed yield is being manifested as the cumulative effect of heterosis for component traits. In the present investigation, the study of ten crosses revealed the fact as most of the crosses that showed positive and significant heterosis for yield, also showed for number of capsules plant-1, length of capsule, number of seeds capsule-1 and 1000-seed weight, the major yield contributing characters. All the hybrids exhibited significant positive standard heterosis for this trait. Hybrid JLT 8 x ES 3 showed higher value for standard heterosis (54.05%). This cross also gave highest standard heterotic values for number of capsules plant-1, length of capsule and number of seeds capsule-1. The findings of the present investigation on the magnitude of heterosis for seed yield plant-1 are consistent with the earlier reports of Ragiba and Reddy (2000) and Singh et al. (2007). The expression of hybrid vigour in F1 usually breaks down in the F2 and subsequent generations due to segregation of heterotic gene complex. To assess the extent of reduction in performance, F2 generation was raised and magnitude of inbreeding depression was estimated for the various traits (Table 1). Shull (1914) reported that the high inbreeding depression (positive) is the reflection of higher heterosis especially in cross pollinated crops. In the present study, it may be seen that the hybrids which showed higher estimates of heterosis, in general, was found to reflect substantial inbreeding depression. Negative and significant inbreeding depression was observed for days to 50% flowering and days to maturity. It indicates the possibility of getting transgressive segregants in advanced generations. The hybrids which exhibited high heterosis for grain yield also showed high and significant inbreeding depression. The magnitude of inbreeding depression ranged from 8.68% to 19.85%. Hybrid with significant heterosis in F1 and high degree of inbreeding depression in F2 could be attributed due to high magnitude of non-additive gene effects. Similar finding were also reported by Ragiba and Reddy (2000) in sesame and Ram et al. (2009) in barley crop for various traits. Thus, hybrid JLT 8 x ES 3 registered highest significant standard heterosis followed by GT 1 x ES 3 for seed yield per plant, number of capsules per plant, length of capsule and number of seeds per capsule. So parents of these hybrids can
be exploited for further improvement and getting better hybrids in sesame.
SUMMARY Study was conducted to determine heterosis in F1 hybrids and inbreeding depression in F2 generation of ten sesame (Sesamum indicum L.) crosses with respect to seed yield and its component traits. Among the hybrids, JLT 8 x ES 3 recorded highest relative heterosis (38.85%), heterobeltiosis (20.57%) and standard heterosis (54.05%) for seed yield plant-1. This cross followed by cross GT 1 x ES 3 was superior in terms of number of capsules plant-1, length of capsule and number of seeds capsule-1. Negative inbreeding depression was observed for days to 50% flowering and days to maturity. Yield plant-1 and number of capsules plant -1 showed considerable inbreeding depression in F2 generation.
REFERENCES Duhoon SS, 2004. Exploitation of heterosis for raising productivity in sesame. 4th International Science Congress. Brisbane, Australia. Dusane SM, Surve US and Rodge RG, 2002. Studies on exploitation of useful heterosis in Sesamum indicum L. Agricultural Science Digest 22: 108-110. FAO, 2008. Food and Agricultural Organization. Database 2008, www.fao.org. Hays HK, Immer FR and Smith DC, 1955. Methods of Plant Breeding. Mc-Graw Hill Book Company, U.S.A. Kempthorne O, 1957. An Introduction to Genetic Statistics. John Willy and Sons Inc., New York. Kumaresan D and Nadarajan N, 2004. Heterosis for yield and yield components in sesame (Sesamum indicum L.). Research on Crops 4: 373-376. Ragiba M and Reddy CR, 2000. Heterosis and inbreeding depression in sesame (Sesamum indicum L.). Annals of Agricultural Research 21 338-341. Ram Daya, Singh Lokendra, Singh SK and Kumar Jitendra, 2009. Heterosis and inbreeding depression in barley (Hordeum vulgare L.). Current Advances in Agricultural Sciences 1: 2729. Reddy SSL, Sheriff RA, Ramesh S and Rao AM, 2001. Heterosis across several characters in sesame (Sesamum indicum L.). Mysore Journal of Agricultural Sciences 35: 55-57. Shull GH, 1914. Duplicate genes for capsule form in bursa. Bursa Nastosis Zeitscher Induktiv. Abstanimu. Vererbunglehana 12: 97-100. Singh AK, Lal JP, Kumar H and Agrawal RK, 2007. Heterosis in relation to combining ability for yield and its components in sesame, Sesamum indicum L. Journal of Oilseeds Research 24: 51-55.
