Advances in Life Sciences 6(1), Print : ISSN 2278-3849, 37-39, 2017 Phyllody Resistance in Wide Hybridization of Sesame (Sesamum indicum L.) S.D. RAJPUT AND K.S. RAGHUWANSHI MPKV, Rahuri email : [email protected] ABSTRACT 9:7 (resistant:susceptible) for the control of phyllody resistance. While, Parani et al. (1996) suggested that the The research work was carried out to study the mode of resistance maybe controlled by a single recessive gene in inheritance of resistance to phyllody disease in a cross of wild species. Shinde et al. (2011) revealed that phyllody sesame derived from wide hybridization. An infector row resistance is under the control of two dominant genes with technique was used for evaluatingthe parents with their complementary gene action (9:7). F1, F2, B1 and B2plants for phyllody resistance. No insecticide was sprayed in order to maintain the natural MATERIALS AND METHODS leaf hopperpopulations in experimental field. The scoring The source of resistance to phyllody are very rare in of the test materials was done by phyllody disease rating the germplasm of sesamum, whereas a high proportion scale. According to the per cent disease incidence (PDI) ofresistance to phyllody disease are available in wild score, the sesame breeding lines were categorized into0 species viz. sesamum malbaricum, sesamummulyanum, to 100 per cent under 0 to 4 grades,plants were immune O sesamumprostratum Srinivasalu (1991). et.al reported that. grade, with 1 grade (1-10%) and moderately resistance Sesamum mulyanucum contains desirable genes for with 2 grade (10.1-25%).Allthese were included in phyllody resistance. Therefore back cross method was used resistance class. While in susceptible group, moderately for the development of introgressed breeding line viz., JLW- susceptible with 3 grade (25.1-50%) and highly 620.The inter specific cross was made between genotype JLT-7 of sesamum indicum species and wild relative of susceptible with 4 grade (>50%).However, pooling the sesamum mulyanum species. The resulted F again back families of resistance reactions (immune, resistant and 1 crossed with sesamum mulyanum till BC generations. The moderately resistant) into one class as resistant and 7 resulted introgressed breeding line JLW620 was identified families of susceptible reaction (moderately susceptible through field screen to phyllody resistant.This moderately and susceptible) into another class as susceptible.The resistant lines to phyllody were used in the cross to study F populations and backcross segregation analysis in 2 the inheritance pattern of phyllody resistance. Another thecross made between moderatelyresistantand moderately breedingline JLS-116 was indentified for moderately susceptible genotypes to phyllody,revealed that a single susceptible to phyllody through field screening. A cross recessive gene governed phyllody resistance in cross viz.,JLW-620 x JLS-116 (Resistance-introgressed material x JLW-620 x JLS-116which segregated independently.In the Susceptible) were effected by hand emasculation and cross JLW-620 x JLS-116, monogenic resistance (1R:3S) pollination for raising F1 generation during kharif 2011 to segregation pattern was observed.The F2populations study the inheritance of phyllody resistance. The selfing showed that the dominance of susceptibility over the of F1 generation and back crosses were effected to obtain resistance. enough self seed and back cross generations during summer 2012. The parents with their F1, F2, B1 and B2 were Key words Sesame, inheritance, resistance, phyllody, evaluated at Post Graduate Research Farm of Department gene action. of Botany, Mahatma Phule Agricultural University, Rahuri during kharif 2012. For higher attack of phyllody sowing was delayed tillmid July and screening was done after Sesame (Sesamum indicum L.) is one of the oldest making an effort to transmit the disease by the leafhopper, and traditional oilseed crops grown in India. Major factors (Orosiusalbicinctus ) from periwinkle (Catharanthus roses) that limit its productivity besides narrow genetic base are and sunhem (Crotolariajuncea) maintained nearby as an extreme susceptibility to biotic and abiotic stresses. alternate host to the healthy sesame plants. Parents, F s, Phyllody, an important disease of sesame is caused by a 1 F B , B were screened in field for their reaction against pleomorphic mycoplasma-like organism (phytoplasma) and 2, 1 2 phyllody disease using infector row technique (Paraniet transmitted by leaf hopper. The affected plants become al.,1996.).The moderatly susceptible variety AT-183 was stunted and the floral parts get modified into leafy structures used as infector row. The disease incidence was measured bearing no fruits and seeds causing yield loss up to 100 per as disease intensity percentage by counting the number of cent.Phyllody control is often based on limiting the vector plants infected. Based on the intensity of infection the population with insecticides, which are ineffective under disease reaction were recorded in 0-4 % grade scale severe leaf hopper infestations. The use of resistance (Shindeet al.,2011.) i.e.The incidence of the disease on ten verities is the most desirable strategy to manage the disease plants each in P , P and F , 50 plants in B , B and 400 in an economical and environmentally friendly way. 1 2 1 1 2 plants in F at weekly interval at 51,58,65,72 DAS was Successful breeding of resistant variety depends upon the 2 recorded. The chi-square test was performed to determine availability of dependable resistant source(s) and a clear the goodness of fit of observed segregation for phyllody understanding of its genetics.Information on inheritance disease reaction in B , B and F generations. of resistance to phyllody disease is useful in breeding for 1 2 2 resistant cultivars.Singhet al. (2007) obtained the ratio of 3 8 Advances in Life Sciences 6(1), 2017 Table1. Incidence of phyllody in JLW-620 x JLS-116 cross of sesamum Generations Percentage of incidence Reaction 51DAS 58 DAS 65 DAS 72DAS P1(JLW-620) 0.00 0.00 10.00 20.50 Moderately Resistance (0.00) (0.00) (18.41) (26.91) P2(JLS-116) 0.00 0.00 20.00 90.00 susceptible (0.00) (0.00) (26.54) (71.92) F1 (JLW-620 x JLS-116) 0.00 0.00 30.00 90.00 susceptible (0.00) (0.00) (33.18) (72.44) F2 JLW-620 x JLS-116 5.50 11.00 23.75 77.00 susceptible (13.55) (19.35) (29.17) (61.41) BC1 (JLW-620 x JLS-116) x JLW- Moderately 10.00 16.00 30.00 44.00 620 Susceptible (18.41) (23.55) (33.18) (41.55) BC2 (JLW-620 x JLS-116) x JLS- 12.00 22.00 36.00 54.00 susceptible 116 (20.24) (27.94) (36.87) (47.31) * Bold italic figures indicate arcsine transformed values maturity indicating that susceptibility was dominant over RESULTS AND DISCUSSION resistance.Similar results werereported by Singhet al. (2007). Phyllody disease is wide spread in the major sesamum In BC1 generation of the cross JLW-620 x JLS-116out growing areas in India. Resistance to phyllodydisease was of 50 plants, 28 were resistant and 22 were susceptible. determined by visual symptomatology. Symptomless lines These numbers fit very well with the ratio 1 Resistant: were assumed to be resistant. As sesamum lines can be 1Suceptible expected from the segregation of two loci with infected without showing symptoms, it is possible that these 2 a c value of 0.72.While in BC2, out of 50 plants 23 were are not resistant lines. Breeding for cultivars with resistance resistant and 27 were susceptible. These numbers also fit is a commonly accepted and effective strategy for very well with the 1:1 i.e.1Rsistant:1Suceptible expected controlling the phyllody disease and also prevent the from the segregation of two loci with c2 value 0.32.(Table 2) multiplication of mycoplasma. The knowledge of inheritance In F generation of the cross, JLW-620 xJLS-116itwas of resistance gene and role of each gene in the development 2 of resistance or susceptibility will be very useful for the further confirmed by screening 400 randomly selected plants sesamum breeder to breed phyllody resistance varieties. to the incidence of phyllody disease. The data revealed The objective of this study was to determine the inheritance that, the per cent disease incidence (PDI) against phyllody of phyllody resistance in specific cross of sesamum. From ranged from 0 to 100 per cent under 0 to 4 grades.Out of the the pathological parameters (PDI) evaluated, the breeding 400 families, 32 plants were immune with O grade, 30 were line JLW-620 demonstrated their moderately resistance to resistant with 1 grade (1-10%) and 30 were moderately phyllody; while AT-183 and JLS-116 were appeared to be resistance with 2 grade (10.1-25%).Allthese 92 plants were moderately susceptible.The results are presented in Table included in resistance class. While in susceptible group, 1.In JLW-620 x JLS-116cross moderately resistance 308 plants were included, out of which 249 were moderately introgressed breeding line JLW-620 was crossed with susceptible with 3 grade (25.1-50%) and 59 were highly susceptible with 4 grade (>50%). However, pooling the phyllody susceptible parent JLS-116. In F1 of the cross JLW- 620 x JLS-116, 72.44% phyllody incidence was observed at families of resistance reactions (immune, resistant and Table 2. Chi square test for goodness of fit with standard ratios in the segregating generations Against phyllody. Combinations Generations Segregation Expected 2 Observed Expected Ratio R :S Total resistant susceptible Total resistant susceptible JLW-620 x JLS-116 F2 400 92 308 400 100 300 1:3 0.85 (JLW-620 x JLS-116) BC1 (F1 x JLW- 50 28 22 50 25 25 1:1 0.72 x JLW-620 620) (JLW-620 x JLS-116) BC2 (F1 x JLS- 50 23 27 50 25 25 1:1 0.32 x JLS-116 116) RAJPUT and RAGHUWANSHI, Phyllody Resistance in Wide Hybridization of Sesame (Sesamum indicum L.) 3 9 moderately resistant) into one class as resistant and families lineJLW-620can be used as potential source for resistance of susceptible reaction (moderately susceptible and to phyllody and it is suggested that they can be use as susceptible) into another class as susceptible, showed the donor parent in the resistant breeding programme in monogenic segregation of 3 Susceptible: 1 Resistance which sesamum.