Final SPH -JHS Coverpage 17-1 Jan 2022 single 25 J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 This is an open access article d istributed under the terms of Creative Commons Attribution-NonCommer cial-ShareAl ike 4.0 International License, which permits unrestricted non-commercial use, d istribution, and reproduction in any med ium, provide d the original author and source are credited. Original Research Paper INTRODUCTION Ridge gourd (Luffa acutangular (Roxb.)L.) is an important cucurbitaceous vegetable crop grown in tropical and subtropical countries, especially in Asia and India (Jansen et al., 1993). It is a crop grown for immature fruit rich in dietary fibre and minerals (Sheshadri, 1990). In addition to culinary properties, it ha s numer ous medicina l pr oper ties which traditionally used for the treatment of stomach ailments and fever (Burkill, 1985; Chakravarty,1990). Though cultivars of ridge gourd are monoecious, diverse sex forms were reported viz., androecious, gynoecious, gynomonoecious, andromonoecious and hermaphrodite types (Choudhary and Thakur, 1965). The female flowers are solitary whereas male flowers are in racemes. Principally 2 genes are involved in production of various sex forms (Richaria, 1948). Male sterility is of practical importance in vegetable breeding as it facilitates F1 hybrid seed production without hand pollination. Male sterility in ridge gourd was first reported from India by Deshpande et al. (1979) and then by Pradeepkumar et al. (2007). Male sterility is governed by single recessive nuclear gene in water melon (Hexun et al., 1998; Ping et al., 2010); musk melon (Dhatt and Gill, 2000; Park et al., 2009), cucumber (Zhang et al., 1994) and for the first time, cytoplasmic male sterility (CMS) with two dominant restorer genes has been reported in ridge gourd by Pradeepkumar et al. (2012). At ICAR-IIHR, Bengaluru also male sterile mutants were identified in ridge gourd germplasm (Varalakshmi and Deepak, 2017). Present study was conducted to characterize that male sterility observed, to work out the genetics of its inheritance and to develop male sterile and maintainer lines in different genetic backgrounds of ridge gourd. MATERIALS AND METHODS The work was undertaken in the experimental field of Division of Vegetable crops, ICAR-IIHR, Bengaluru. Initially two male sterile mutant plants viz.,IIHRRG- 12MS and IIHRRG-28MS in different genetic backgrounds have been identified during kharif, 2015- 16 and ma inta ined in the division ever since. Morphological characters of these male sterile mutants were recorded viz., days for emergence of first fertile male flower, days for emergence of ûrst female flower, node at which first fertile male flower appeared, node at which first female flower appeared, male bud length Characterization, inheritance of male sterility and development of male sterile and maintainer lines in ridge gourd (Luffa acutangula (Roxb.) L.) Varalakshmi B.1* and Rajasekharan P.E.2 1Division of Vegetable Crops, 2Division of Flower and Medicinal Crops, ICAR-Indian Institute of Horticultural Research, Bengaluru - 560 089, Karnataka * Corresponding author Email : Varalakshmi.B@icar.gov.in ABSTRACT Two male sterile mutants IIHRRG-12MS (long fruited) and IIHRRG-28MS (medium long fruited) were identified from the ridge gourd germplasm IIHR-12 and IIHR-28 respectively at ICAR-IIHR, Bengaluru. These two male-sterile (ms) sources were characterized by the production of rudimentary male flowers in the racemes in contrast to the bright yellow flowers with fertile pollen and healthy anthers in male fertile, monoecious plants. Using these ms lines the inheritance of male sterility was worked out, which is cytoplasmic genic male sterility (CGMS) type, with single dominant gene either in homozygous or heterozygous condition restoring male fertility in the presence of sterile cytoplasm. In order to develop F1 hybrids using male sterility, several male sterile and maintainer lines were developed in different genetic back grounds such as green/dark green fruit colour and short/medium long/long fruit length. Keywords: CGMS, gene action, inheritance, maintainer lines, male sterility and ridge gourd 26 Varalakshmi and Rajasekharan J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 and pollen fertility (%). Pollen fertility percentage was assessed from ten randomly selected male ûower buds in each line at anthesis on the basis of stainability in acetocarmine and the counts were taken from ten fields under microscope for each flower bud. Well filled, uniformly and darkly stained pollen grains were consider ed a s fer tile a nd the r est a s ster ile. Simultaneously, these ms plants were crossed with 22 monoecious lines viz.,IIHR-1, IIHR-7, IIHR-10-2, IIHR-11, IIHR-12, IIHR-17-2-1-6, IIHR -19, IIHR- 23, IIHR-26, IIHR-27, IIHR-29, IIHR-31, IIHR-34, IIHR-35, IIHR-39, IIHR-40, IIHR-41, IIHR-43, IIHR-46, IIHR-47, IIHR-49 and IIHR-72-2 to study the inheritance of male sterility and fertility restoration in ridge gourd during kharif season of 2015-16. All the 22 F1 hybrids and parental lines were grown with recommended package of practices during Rabi- summer season of 2016-17. Observations pertaining to male and female fertility were recorded from 15 plants in each line/hybrid. Among the 22 hybrids, 10 fer tile hybr ids (IIHRRG-28MS x IIHR-10-2, IIHRRG-28MS × IIHR-72-2, IIHRRG-12MS × IIHR -17-2-1-6, IIHRRG-12MS x IIHR-1, IIHRRG-12MS x IIHR-12, IIHRRG-12MS x IIHR-40, IIHRRG- 12MSx IIHR-41, IIHRRG-12MS x IIHR-43, IIHRRG-12MS x IIHR-47 and IIHRRG-12MS x IIHR-49) were selfed to generate F2 population as well as back crossed with respective male parent to produce BC1 generation. Five hybrids were male sterile viz.,IIHRRG-12MSxIIHR-19, IIHRRG-12MSxIIHR- 27, IIHRRG-12MSxIIHR-31, IIHRRG-12MSx IIHR- 34 and IIHRRG-12MSxIIHR-39. Remaining seven hybrids were not uniform with respect to fertility (IIHRRG-12MSxIIHR-7, IIHRRG-12MSxIIHR-11, IIHRRG-12MSxIIHR-23, IIHRRG-12MSxIIHR-26, IIHRRG-12MSxIIHR-29, IIHRRG-12MSxIIHR-35 a nd IIHRRG-12MSxIIHR-46) a nd wer e not considered further in the study. F2 population (200 plants), BC1 generation (50 plants) were raised during the kharif season, 2017-18 and evaluated for male sterility and restoration of fertility. Chi-square (χ2) goodness-of-fit analysis (Russell, 1996) was conducted for segregation of male fertility and sterility in F2 populations of two crosses viz., IIHRRG-12msx IIHR- 17-2-1-6 and IIHRRG-28msx IIHR-72-2. In order to transfer the male sterility in to different genetic backgrounds, crosses were made between male sterile lines and ten different advanced breeding lines with different genetic backgrounds to convert them into ms lines as well as maintainer lines viz., IIHR-6- 2(long, green), IIHR-5-1-2 (Medium long, green), IIHR-37-4-1, IIHR-23-5-4, IIHR-34-2-2, IIHR-49-3- 1, IIHR-22-4-2, IIHR-26-4-2, IIHR-70-1 and IIHR- 11-1-2. Ma le ster ile pr ogeny wa s r epea tedly backcrossed with the male parents (maintainer lines) for six generations to develop the male sterile (A line) and maintainer lines (B line). RESULTS AND DISCUSSION Characterization of male sterility in ridge gourd Male sterility is defined as failure of plant to produce the functional anthers, pollen or male gametes. At ICAR-IIHR, two male sterile mutants were identified in IIHRRG-12 (long fruited) and IIHRRG-28 (medium long fruited) germplasm lines. These two ms sources viz., IIHRRG-12MS and IIHRRG-28MS wer e characterized by the production of rudimentary male flowers in the racemes in contrast to the bright yellow flowers with fertile pollen and healthy anthers in male fer tile, monoecious pla nts (Fig.1 a nd Fig. 2). Rudimentary male buds remained unopened and fell down 12–16 days after the emergence. Similar Fig. 1. Characterization of male sterility in Ridge gourd Rudimentary male flowers Fertile male flowers Sterile and Fertile pollen 27 Male sterile and maintainer lines in ridge gourd characteristics of the male sterile line were reported by Pradeepkumar et al. (2010) in ridge gourd. Expression of male sterility and restoration of fertility in F1 hybrids Hybrids have expressed different fertility status, viz., complete sterile, complete fertile and some hybrids with both fertile and sterile plants. If male sterility was controlled by dominant gene, which was a rare phenomenon in cucurbits, all the hybrids should have expressed complete sterility in F1 generation, then as all the individuals carrying Ms allele are sterile and do not produce progenies as pollen parents. If it is controlled by recessive nuclear gene as in musk melon (Park et al., 2009), water melon (Ping et al., 2010), squash (Carle, 1997) and cucumber (Zhang et al., 1994), then F1 should have segregated into 1:1 fertile a nd ster ile pla nts ba sed on the homozygosity/ heterozygosity of the locus controlling the sterility. But here in this case, male sterility expression of F1 hybrids indicates the role of CMS genes. CMS is maternally inher ited a nd is a ssocia ted with a specific (mitochondrial) gene whose expression impairs the production of viable pollen without otherwise affecting the plant (Kempken and Pring, 1999; Budar and Pelletier, 2001). Premature degeneration of the tapetum at the early to mid uni-nucleate microspore stage leads to the development of non-viable pollen (Roberts et al., 1995). General theory about the phenotype of CMS plants which usually appear normal, vigorous, and undistinguishable from the fertile analogue (Hanson and Conde, 1985) proved true in the present study also. There are nuclear genes that can restore fertility, termed nuclear restorer (Rf) or fertility restorer (Fr) genes, which are specific for each studied CMS system (Popova et al., 2007). The restorer of fertility (Rf) genes in the nucleus function to suppress the CMS phenotype and restore the male fertility. Dominant nuclear fertility restorer gene in ‘IIHR-1, IIHR-10-2, IIHR-12, IIHR -17-2-1-6, IIHR-40, IIHR-41, IIHR- 43, IIHR-47, IIHR-49, IIHR-72-2’ out of 22 genotypes is responsible for regaining male fertility of hybrids with ms mutant line. All these ten lines could be possible restorer lines. Seven other cr osses (IIHRRG-12MSxIIHR-7, IIHRRG-12MSxIIHR-11, IIHRRG-12MSxIIHR-23, IIHRRG-12MSxIIHR-26, IIHRRG-12MSxIIHR-29, IIHRRG-12MSxIIHR-35 and IIHRRG-12MSxIIHR- 46) had both male sterile and male fertile plants in different ratios indicating that the fertility restorer genes might be in heterozygous condition in these inbred lines which can be used to develop either maintainer lines or restorer lines a fter progeny evaluation and back crossing. Five hybrids viz.,IIHRRG-12MSxIIHR-19, IIHRRG- 12MSxIIHR-27,IIHRRG-12MSxIIHR-31, IIHRRG- 12MSxIIHR-34 and IIHRRG-12MSxIIHR-39 were male sterile indicating the maintenance of sterility and these advanced breeding lines could be possible maintainer lines. Though the five male pa rents exhibited high pollen fertility (52-83%), they failed to transmit this character to F1 hybrids indicating the cytoplasmic inheritance of male sterility in ridge gourd. The average bud length of male buds of male sterile hybrids at full development stage was found to be 0.6±0.01cm which was significantly different from the average bud length of male fertile parents (1.7± 0.05cm) (Supplementary Data Table S1). These rudimentary male buds in racemes of male sterile hybrids remained unopened and fell down 12–16 days a fter the emergence. T he a nther lobes wer e undeveloped and pollen grains were small, shrunken and poorly stained in these hybrids throughout the crop growth indicating a stable sterility mechanism. Male fer tile hybr ids ha d high mea n pollen fer tility (47±6.57%) throughout the crop growth. In the male sterile hybrids node for the first female flower was earlier (9.6th node) compared to the male fertile hybrids (10.2nd node) and also the days taken for the emergence of first female flower is less in male Fig. 2. Male flower production in monoecious line (left) and absence of male flowers in male sterile line (right) J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 28 sterile hybrids (41.2 days) compared to male fertile hybrids (43.4days) (Supplementary data Table S2). Similarly mean female bud length was more (94.8 cm) in male sterile hybrids than male fertile hybrids (4.6cm) and also the fruit length was more in sterile hybrids (24.8cm) than in fertile hybrids (20.2cm) Analysis of F2 population from the crosses, IIHRRG-12MSxIIHR-17-2-1-6 and IIHRRG - 28MSx IIHR-72-2 for male sterility and restoration of fertility: Out of the 239 F2 plants of the cross IIHRRG-12MS x IIHR-17-2-1-6, 182 were male fertile and 57 were male sterile till the end of the season. There were observable differences between the male sterile and male fertile plants with respect to male flower production though female flowers in both types were similar. Node for the first fertile male flower ranged from 2-14th node with the mean of 4.92 and the days taken for the first male flower ranged from 29-51 days with a mean of 42.08 days. Average male flower bud length was less in male sterile plants (0.61cm) compa red to the male fer tile pla nts (1.89 cm) (Supplementary data able S3). Mean pollen fertility of these male fertile plants was 24.95% as against zero fertility of male sterile plants. With respect to female flower traits, there were slight differences between male sterile and male fertile plants. Node for first female flower was earlier in sterile plants (9.4) compared to male fertile plants (10.18), similarly even the number of days taken for first female flower appearance was less in male sterile plants (43.3 days) compared to male fertile plants (45.99). However, the average female flower bud length and fruit length were almost same in both male sterile and male fertile plants. In another F2 population of the cross, IIHRRG-28MSx IIHR-72-2, out of 235 F2 plants, 175 were male fertile and 60 were male sterile. In this cross also there were differences between male sterile as well as male fertile plants with respect to male flower production. Node for the first fertile male flower ranged from 2-8th node with the mean of 4.21 and the days taken for the first male flower ranged from 39-55 days with a mean of 42.84 days. Average male flower bud length was less in male sterile plants (0.63cm) compared to the male fertile plants (1.85 cm). Mean pollen fertility of these male fertile plants was 7.56% as against zero fertility of male sterile plants. With respect to female flower traits, there were slight differences between male sterile and male fertile plants. Node for first female flower was earlier in sterile plants (8.52) compared to male fertile plants (9.82), similarly even the number of days taken for first female flower appearance was less in male sterile plants (42.8 days) compared to male fertile pla nts (44. 38)(Supplementar y data Ta ble S3). However, the average female flower bud length and fruit length were almost same in both male sterile and male fertile plants. All the F1 plants of these two ms x mf crosses and their corresponding back cross populations were male fertile. As the F2 population segregated into two classes in both the crosses, monohybrid ratio, 3:1 was tested for significance using chi-square test. The chi-square value for the 3:1 (fertile: sterile) single dominant gene action exhibited a good fit to the expected ratio (80- 90% probability) (Table 1 and 2). The F 2 data indicated the presence of cytoplasmic genic male sterility (CGMS) in ridge gourd with single dominant gene restoring male fertility in the presence of sterile cytoplasm. However, Pradeepkumar et al. (2012) earlier reported that two dominant fertility restorer genes are responsible for restoration of fertility in the presence of sterile cytoplasm in ridge gourd using Arka Sumeet variety as restorer line. This could be due to different genetic makeup of different male sterile and restorer lines used in these studies. Assuming that MS line is having genotype, rf1rf1 and sterile cytoplasm (S) and male parent, IIHR- 17-2-1-6/IIHR-72-2 possesses a genotype Rf1Rf1 carrying a fertility restorer gene in homozygous dominant state and normal fertile cytoplasm (N), F1 will be male fertile as the genotype of F 1 is SRf1rf1. Though F1 is inheriting a sterile cytoplasm from ma le sterile female pa rent, pr esence of a dominant fertility restorer gene, viz., Rf1 restores the fertility of F1 (Table 3). In F2 presence of single domina nt f e r t ilit y r es t or er gen e in eit her homozygous or heterozygous condition ensures ma le fer tility. The gene action governing ma le sterility can be explained with the following model. Evaluation of back crosses made between fertile hybrids with restorers during summer Three male fertile hybrids were back crossed with restorer lines and all these back cross progenies were male fertile indicating the restoration of male fertility in these lines (restorer lines) (Table 4). Varalakshmi and Rajasekharan J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 29 Cross Genotype F2’s (3:1)   Fertile Sterile (IIHRRG-12MSxIIHR-17-2-1-6) Expected 179 60 F2 population   Observed 182 57   Difference 3 -3   Chi Square value 0.169   Probability 50-70% F2’s (3:1)   Fertile Sterile (IIHRRG-28MSxIIHR-72-2) Expected 176 59 F2 population   Observed 175 60   Difference -1 1   Chi Square value 0.035   Probability 80-90% Table 2. Chi-square test for F2 population segregating for male sterility and male fertility in ridge gourd Cross F1’s Back cross F2’s Fertile Sterile Fertile Sterile Fertile Sterile (IIHRRG-12MSxIIHR-17-2-1-6) 15 0 44 0 182 57 (IIHRRG-28MSxIIHR-72-2) 15 0 37 0 175 60 Table 1. Segregation of male sterile and male fertile plants in F1, Back cross and F2 generation of the crosses, IIHRRG-28MSx IIHR-72-2 and IIHRRG-12MSxIIHR-17-2-1-6 Male sterile and maintainer lines in ridge gourd J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 Parents Male sterile line Male fertile line IIHRRG-12MS/ IIHR-17-2-1-6/ IIHRRG-28MS IIHR-72-2 S(rfrf) N(RfRf ) Gametes S(rf) N(Rf) F1 Male fertile S(Rfrf) Gametes Rf, rf Eggs/pollen Rf Rf Rf SRfRf Male fertile SRfrfMale fertile rf SRfrf Male fertile SrfrfMale Sterile Table 3. Proposed genetic model for Single dominant gene action in ridge gourd BC1 generation of the cross (IIHRRG-28MS × IIHR-72-2) x IIHR-72-2 exhibited increased male fertility compared to F1 (IIHRRG-28MS × IIHR- 72-2). All three BC1­populations  took  little more days to male flower production (45-46) and wide var iation was obser ved a mong the ba ck cr oss populations with respect to the node for the first female flower appearance (4-26th node) and days taken for the emergence of first female flower (34- 65 days) (Table 5). BC populations exhibited pollen fertility in the range of 40-78%. Wide variation was observed for average female bud length (4-6 cm) and fruit length (20-25cm) among the three back cross populations. 30 Table 4. Evaluation of back crosses made between fertile hybrids and fertility restorers - male flower characters Male fertile back cross Node at first Days for the Average Pollen fertile male emergence of male bud fertility flower first fertile male length % flower Range Mean Range Mean Range Mean Range Mean (IIHRRG-28MS × IIHR-10-2) × 2-7 4 39-48 42 1.0-2.6 1.85 19-63 40 IIHR-10-2 (IIHRRG-28MS × IIHR-72-2) × 3-12 5 37-45 42 1.1-2.6 1.91 47-100 74 IIHR-72-2 (IIHRRG-12MS × IIHR - 3-16 5 40-48 43 1.0-2.6 1.80 19-88 58 17-2-1-6) × IIHR -17-2-1-6 Mean   1.0   0.8   0.1   16.8 SEm±   0.6   0.5   0.0   9.7 Varalakshmi and Rajasekharan Development of ms lines (A lines) and maintainer lines (B lines) in different genetic back grounds The identified cytoplasmic male sterility (cms trait) has been transferred to different genetic backgrounds, by crossing ten different advanced breeding lines with different genetic backgrounds viz., IIHR-6-2 (long, green), IIHR-5-1-2 (Medium long, green), IIHR-37- 4-1 (short, green) IIHR-23-5-4 (medium, green), IIHR- 34-2-2, IIHR-49-3-1(medium, green), IIHR-22-4-2, IIHR-26-4-2, IIHR-70-1 (long, dark green) and IIHR- 11-1-2 with male ster ile line (IIHRRG-28MS/ IIHRRG-12MS maintained through sib mating with maintainer line, IIHRRG-28/IIHRRG-12) to convert Table 5. Evaluation of back crosses made between fertile hybrids and fertility restorers - female flower characters Male fertile back cross Node at first Days for the Average Average fertile emergence of female bud fruit length flower first female length (cm) flower (cm) Range Mean Range Mean Range Mean Range Mean (IIHRRG-28MS x IIHR-10-2) × 4-25 12.1 34-62 46 5-7.5 6 16.5-30 25 IIHR-10-2 (IIHRRG-28MS × IIHR-72-2) x 5-15 9.5 34-62 45 5-7.5 6 12.5-30 20 IIHR-72-2 (IIHRRG-12MS × IIHR -17-2-1-6) 4-26 24.0 34-65 45 4-5.5 4 12-28 20 × IIHR -17-2-1-6 Mean   15.2   45.1   5.7   21.8 SEm±   4.5   0.3   0.6   1.7 them into ms lines. All these F1 populations were male sterile due to cytoplasmic inheritance of male sterility in the identified source. These F1’s were repeatedly back crossed with their respective male parents/ maintainer lines for six generations continuously. The back cross population plants which were having similar fruit attributes of maintainer lines in each generation were selected and back crossed with the maintainer line. In each generation the back cross populations were checked for maintenance of sterility and found that all were maintaining sterility in 100% population. Thus, by BC6 generation, all these ten populations viz.,IIHR-6-2MS, IIHR-5-1-2MS, IIHR- 37-4-1MS, IIHR-23-5-4MS, IIHR-34-2-2MS, IIHR- J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 31 49-3-1MS, IIHR-22-4-2MS, IIHR-26-4-2MS, IIHR- 70-1MS and IIHR-11-1-2MS were perfectly male sterile resembling the respective maintainer lines morphologically in different genetic back grounds such as green, dark green, long, medium long, short fruit back grounds (Fig. 3). Thus, these ten maintainer lines IIHR-6-2, IIHR-5-1-2, IIHR-37-4-1, IIHR-23- 5-4, IIHR-34-2-2, IIHR-49-3-1, IIHR-22-4-2, IIHR-26-4-2, IIHR-70-1 and IIHR-11-1-2 proved to possess fertility restorer gene (Rf) in homozygous recessive condition making them as ideal maintainer lines (Pradeepkumar et al., 2018). These 10 sets of male sterile (A lines) as well as maintainer lines (B lines) in different genetic backgrounds (Fig 3) are now ready for the development of hybrids using fertility restorer lines (C lines). This study confirms the presence of CGMS system in ridge gourd paving way for commercial hybrid seed production in this crop as reported by Pradeepkumar et al., (2018), who for the first time developed CGMS system in ridge gourd by developing MS LA 101 and LA 101, male s ter ile ( A line) a nd ma int a iner line (B line) respectively. ACKNOWLEDGEMENT The a uthors wish to acknowledge the fina ncial support provided by ICAR, New Delhi by granting a ‘Flagship Program-Application of male sterility systems to increase the efficiency of F 1 hybrids in horticultural crops: onion, ca rr ot, chilli, r idge gourd, okra and marigold’ and expresses gratitude to the Lea der of the pr oject, late Dr. R. Veer e Gowda for his constant encouragement. Male sterile and maintainer lines in ridge gourd Fig. 3. Fruits of male sterile and maintainer lines in different genetic backgrounds (long/medium/short fruit length and dark green/green fruit color) in ridge gourd IIHR-49-3-1(medium, green) IIHR-6-2 (long, green)IIHR-70-1 (long, dark green) IIHR-37-4-1 (short, green) J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 32 REFERENCES Budar, F. and Pelletier, G. 2001. Male sterility in plants: occurrence, determinism, significance and use. Life Sci. 324: 543–550. Burkill, H.M. 1985. The Useful Plants of West Tropical Africa, Second ed. Royal Botanical G a r dens , K ew. T he W hit ef r i a r s P r es s Limited, London. Carle, R.B. 1997. Bi-sex sterility governed by a single recessive gene in Cucurbita pepo L. Cucurb. Genet. Coop. Rpt. 20: 46–47. Chakravarty, H.H. 1990. Cucurbits in India and their role in development of vegetable crops. I n : B i o l o g y a n d U t i l i z a t i o n o f t h e Cucurbitaceae. Ba tes, D. M. , Robinson, R.W., Jeffrey, C. (Eds.) Cornell University Press, Ithaca, New York, pp.325–348. Choudhary, B. and Thakur, M.R. 1965. Inheritance of sex forms in Luffa. Indian J. Genet. Plant Breed. 25: 188–197. Deshpande, A.A., H. Ravishankar and Bankapur, V.M. 1979. A male sterility mutant in ridge gourd (Luffa acutangular Roxb.). Curr. Res. 6: 97–98. Dhatt, A.S. and Gill, S.S. 2000. Effect of genic male sterility on flowering behaviour of musk melon. Veg. Sci. 27: 31–34. Hanson, M.R. and Conde, M.F. 1985. Functioning a nd va r ia t ion of c ytopla smic genomes : lessons from cytoplasmic-nuclear interactions conferring male sterilities in plants. Int. Rev. Cytol. 94: 213–267. H ex u n, H . , Z . X ia oQi, W. ZhenC heng, L . QingHuai and Xi, L. 1998. Inheritance of male sterility and dwarfism in watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai). Sci. Hortic. 74: 174–181. J a ns en, G. J . , G ildema c her, B. H . a nd Phuphathanaphong, L., 1993. Luffa P. Miller. In: Siemonsma , J. S. a nd Ka s em Pilu ek (Editor s). Plant Resources of South-East Asia No 8. Vegetables. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 194–197. Kempken, F. and Pring, D.R. 1999. Male sterility in higher p la nt s – f u nda me nt a ls a nd applications. Prog. Bot. 60: 139–166. Park, S.O., Hwang, H.Y. and Crosby, K.M. 2009. A genetic linkage map including loci for male sterility, sugars, and ascorbic acid in melon. J. Am. Soc. Hort. Sci. 134: 67–76. Popova, P.K.S., Dimaculangan, D., Radkova, M. and Vulkova, Z. 2007. Towards cytoplasmic male sterility in cultivated tomato. J. Agric. Food Environ. Sci.1: 1–13. Pradeepkumar, T., Sujatha, R., Krishnaprasad B.T. and Johnkutty, I. 2007. New Source of male sterility in ridge gourd (Luffa acutangula (L.) Roxb.) and its maintenance through in vitro culture. Cucurbit. Genet. Coop. Rpt.30: 60– 63. Pradeepkumar, T., Hegde, V.C., Sujatha, R. and George, T.E. 2010. Cha racter iza tion a nd maintenance of novel source of male sterility in r idge gour d (Lu ffa ac uta ngu lar (L . ) Roxb.). Curr. Sci. 99: 1326–1327. Pr a deepkuma r T. , Hegade, V. C., Ka nna n, D. , Sujatha, R., George, T.E. and Nirmaladevi, S. 2012. Inheritance of male sterility and presence of dominant fertility restorer gene in ridge gourd (Luffa acutangula (Roxb.) L.). Scientia Horticulturae. 144: 60–64. Pradeepkumar, T., Minimol, J.S., Deepu Mathew, Veni, K., Roch, V.C., Chithira, P.G. and R a jeshwa r y, U. 2 0 1 8 . Develop ment of C G M S s ys t em in r idge g ou r d [ L u f f a acutangula (Roxb.) L.] for production of F1 hybrids. Euphytica. 214:159 Richa ria , R.H. 1948. Sex inherita nce in Luffa acutangula. Curr. Sci. 17: 358. Roberts, M., Boyes, E. and Scott, R. 1995. An investigation of the role of the anther tapetum during microspore development using genetic cell ablation. Sex Plant Reprod. 8: 299–307. Russell, P.J. 1996. Genetics, fourth ed. Harper Collins College Publication, New York. J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 33 Sheshadri, V.S. 1990. Cucurbits. In: Vegetable Crops in India. Bose, T. K. , Som, M. G. (Eds.), Nayaprakash publishers, Calcutta, pp. 91–164. Varalakshmi, B and Deepak, G.C. 2017. Identification of male sterility, its inheritance and fertility restoration in ridge gourd [Luffa acutangula (Roxb. ) L. ]. Abstr a cts of Inter na tiona l Symposium on Horticulture : Priorities and Emerging Tr ends, 5-8th September, 2017, Bengaluru, India.pp.182. Ping, Z.Y., L. He, X.H., Bin and Peng, G.S. 2010. mRNA differential display between the male s t er ile b u ds a nd ma le f er t il e b u ds in watermelon male sterile G17ABline. J. Fruit Sci. 27: 1037-1041. Zhang, Q., Gabert, A.C. and Baggett, J.R. 1994. Char acterizing a cucumber pollen sterile mutant: inheritance, allelism, and response to chemical and environmental factors. J. Am. Soc. Hort. Sci. 119: 804-807. Male sterile and maintainer lines in ridge gourd J. Hortl. Sci. Vol. 17(1) : 25-33, 2022 (Received: 24.06.2021 ; Revised: 11.112021; Accepted: 22.12.2021 ) 00 A Final SPH -JHS Coverpage First 2 pages.pdf 00 Content and in this issue.pdf 01 Mohan Kumar G N.pdf 02 Meera Pandey.pdf 03 Biradar C.pdf 04 Varalakshmi B.pdf 05 Vijayakumari N.pdf 06 Barik S.pdf 07 Sajid M B.pdf 08 Ranga D.pdf 09 Usha S.pdf 10 Manisha.pdf 11 Amulya R N.pdf 12 Akshatha H J.pdf 13 Adak T.pdf 14 Sujatha S.pdf 15 Gowda P P.pdf 16 Subba S.pdf 17 Dhayalan V.pdf 19 Ahmed S.pdf 20 Vishwakarma P K.pdf 21 Deep Lata.pdf 22 Udaykumar K P.pdf 23 Nayaka V S K.pdf 24 Sahel N A.pdf 25 Bayogan E R V.pdf 26 Rathinakumari A C.pdf 27 Yella Swami C.pdf 28 Saidulu Y.pdf 29 Sindhu S.pdf 30 Neeraj.pdf 31 Sivaranjani R.pdf 32 Rashied Tetteh.pdf 34 Sangeetha G.pdf 35 Shareefa M.pdf 36 Last Pages.pdf