Eco. Env. & Cons. 26 (November Suppl. Issue) : 2020; pp. (S408-S414) Copyright@ EM International ISSN 0971–765X

Flowering pattern and floral architecture of Wild and cultivated varieties of Jamun ( cumini L.) for pollination and productivity

Eswarappa, G.* and Somashekar, R.K.

Department of Environmental Science, Jnanabharathi Campus, Bangalore University, Bangalore 560 056, Karnataka, India

(Received 20 May, 2020; Accepted 8 June, 2020)

ABSTRACT Flowering pattern and phenology of crops are very important in management, productivity and various ecosystem services. Very little is known about the phenology of wild and cultivated varieties of Jamun (Syzygium cumini L.). Four cultivated varieties (GKVK-1, GKVK-2, K-45 and N-20) and two wild varieties at Ponnampet and GKVK locations (wild S. cumini at Ponnampet and wild S. cumini at GKVK) were selected for this study. The initiation of inflorescence from inter nodal region of tagged branches of Syzygium cumini variety GKVK -1 was observed during 2nd week of January followed by GKVK-2, wild S. cumini at Ponnampet and wild S. cumini at GKVK, Bengaluru during 3rd week of January and in K-45, N-20 during 4th week of January 2018. The number of days required from initiation of inflorescence to first opening ranged from 40±0.82 (K-45) to 46±0.82 (wild S. cumini at Ponnampet). The initiation of flowering, 50 and 100 per cent flowering was observed in the 1st, 3rdand 4th week of March respectively in all cultivated varieties (GKVK-1, GKVK-2, K-45 and N-20) and wild S.cumini at Ponnampet, wild S. cumini at GKVK with the exception of variety GKVK-1. The flower opening pattern of wild and cultivated varieties of S.cumini was clearly indicated that once, the opening floral buds started in an inflorescence, it is continued upto upto six days in wild S. cumini at GKVK, K-45, N-20 varieties and up to seven days in wild S. cumini at Ponnampet, GKVK-1 and GKVK-2 varieties. These findings revealed as taggered pattern of flower opening in S. cumini inflorescence for the period of one week. There are eight ovules per flower were observed with longevity of flower lasting for three days and the wilting of flower and dropping of stamens were observed at 4th day after flower opening. The floral architectural differences especially, the difference in the length of stamen and carpel and also the extension of stigma out of the stamens indicated the need of cross pollination by external agents for proper set and fruit yield.

Key words : Jamun, Syzygium cumini, Wild and cultivated varieties, Flowering pattern, Floral architecture

Introduction of India (Reddy and Reddy, 2008). This spe- cies is endemic to south East Asia and India, but Among several tropical in India, jamun also reported to be growing in Hawaii, Australia, (Syzygium cumini L.) is an evergreen multipurpose Philippines, Kenya, Florida (Swami et al., 2012; belonging to the family , consisting of Solomon et al., 2014). It has gained tremendous im- over 75 species and is native of India. A list of 18 portance and recognition in the recent past because Syzygium species included in the international of its medicinal and nutritional properties. Tradi- union for the conservation of nature (IUCN) Red list tionally, jamun fruits, leaves, seeds and bark are all ESWARAPPA AND SOMASHEKAR S409

used in ayurvedic medicine in India (Chaudhary The total days required for the initiation of inflores- and Mukhopadhyay, 2012). The bark contains cence to first flower opening was calculated. The tannins and , accounting for its long- numbers of floral buds opened per inflorescence in term usage as an astringent to combat ailments par- all the branches of selected four were visually ticularly dysentery(Swami et al., 2012). A glycoside observed starting from the period of first flower in the seed, jamboline, is considered to have anti- opening till the end of flowering. The categorisation diabetic properties. Jamun fruit, seeds and pulp of 50% and 100% flowering was made based on the have been reported to serve various purposes in total number of inflorescences developed and the diabetic patients, like lowering blood glucose levels total number of opened. The flower opening and delaying diabetic complications, including neu- pattern was studied on randomly selected four in- ropathy and cataracts (Ayyanar and Subash - Babu, florescence having matured floral buds in four dif- 2012). Jamun is most often recognized as an adju- ferent directions. The numbers of floral buds in each vant therapy in type-2 diabetes (Swami et al., 2012). inflorescence was counted and observed daily till all However, the information regarding flower open- the floralbuds became completely open. On the ing pattern and floral architecture of wild and culti- evening of each day, the number of flowers opened vated varieties of jamun (S. cumini L.) in relation to was removed to avoid confusion. The architectural pollination and productivity is limited. The knowl- characteristics of the flower such as flower length, edge of the phenology of a particular crop is impor- flower width, number of flowers per inflorescence, tant for proper management, productivity and vari- number of sepals per flower, number of petals per ous ecosystem and pollination services; hence the flower, number of stamens per flower, length of sta- present study was undertaken. men, length of carpeland number of ovules per flower were recorded in the laboratory by taking the Materials and Methods cross section of ovary (Pias and Guitian, 2001; Grif- fin and Barrett, 2002). The ten freshly opened flow- The observations on initiation of inflorescence, first ers were randomly selectedfrom the inflorescence flower opening, number of days taken for first offour trees each of wild and cultivated varieties of flower opening, period of commencement of flower- S. cumini were tagged. The freshness of the tagged ing, time of 50% and 100% flowering, average num- flower and stamen drop was visually observed from ber of floral buds per inflorescence and flower open- the day of tagging and longevity of each sampled ing pattern were recorded on four cultivated variet- flower was determined. ies of S. cumini viz., GKVK-1, GKVK-2, K-45, N-20 Statistical Analysis in jamun orchard which were of six years old, planted at the spacing of 5m x 5m during 2012 and The results were analyzed and descriptive statistics on wild S. cumini of more than twelve years old at were done using SPSS 12.0 (SPSS Inc., an IBM Com- Regional Horticultural Research and Extension Cen- pany, Chicago, USA) and graphs were generated tre, College of Horticulture; UHS sub campus, using Sigma Plot 7 (Systat Software Inc., Chicago, GKVK, Bengaluru and also at College of forestry, USA). Ponnampet, Kodagu districton wild S. cumini of more than fifteen year old. The four randomly se- Results and Discussion lected branches of wild and cultivated varieties of S. cumini in four different directions were observed The observation on flowering behaviour of wild and daily starting from January 2018 for the develop- cultivated varieties of S.cumini includes the initia- ment of sprout at the inter nodal region and date of tion of sprout at the internodal region of the sprout initiated was recorded and treated as period branches for the growth and development of inflo- for the inflorescence initiation. The four developed rescence. The sprouts at the emerging stage were sprout from the branches of wild and cultivated selected randomly from four branches in four differ- varieties of S. cumini were selected in four different ent directions from wild S. cumini at Ponnampet, directions were tagged and observed daily for open- wild S. cumini at GKVK, cultivated varieties; GKVK- ing of first flower. The date of first flower opened 1, GKVK-2, K-45 and N-20 were visually observed was recorded and treated as a day of first flower daily during January 2018. The results on flowering opening/ period of commencement of flowering. behaviour revealed that, initiation of the sprout in S410 Eco. Env. & Cons. 26 (November Suppl. Issue) : 2020 the tagged branches of wild S. cumini at Ponnampet GKVK-2 during 3rd week, in K-45 and N-20 during and wild S. cumini at GKVK location was observed 4th week of January. The first flower of fully grown during 3rd week of January and the first flower of inflorescence from the sprout of GKVK-1 was fully grown inflorescence from the same sprout was opened during 3rd week of February and the sprout opened during 1st week of March with a total dura- from GKVK-2,K-45 and N-20 was opened during 1st tion ranged from 45±2.2 (wild S. cumini at week of March with a total duration from initiation Ponnmpet) to46±0.82 (wild S. cumini at GKVK) of inflorescence to first flower opening was ranged days. Among the cultivated varieties, initiation of from 40±0.82(K-45) to 44±1.41 (GKVK-2) days (Plate the sprout in the tagged branches of GKVK-1was 1: a to e). It was clearly observed that, the number of observed in 2nd week of January where as in case of days taken for initiation of inflorescence to first

Plate 1. Days required for initiation of inflorescence to first flower opening inwild and cultivated Varieties of S.cumini : a) Bud tagged at initiation stage b) to d): Bud elongation e) & f): Flower bud initiation g) Opening of flower.

Table 1. Flowering behavior in wild and cultivated varieties of S. cumini at Ponnampet and GKVK during 2018 Wild/ Initiation of First No. of Period of Time of 50% Time of 100% cultivated inflorescence flower days initiation of flowering flowering varieties opening taken for flowering first flower opening Wild S. cumini 19/01/18 04/03/18 45±2.2 March 1st week 3rd week of March 4th week of March (At Ponnampet) Wild S. cumini 17/01/18 03/03/18 46±0.82 March 1st week 3rd week of March 4th week of March (At GKVK) GKVK-1 11/01/18 20/02/18 41±1.83 Feb 3rd week 2rd week of March 3rd week of March GKVK-2 21/01/18 05/03/18 44±1.41 March 1st week 3rd week of March 4th week of March K-45 22/01/18 02/03/18 40±0.82 March 1st week 3rd week of March 4th week of March N-20 24/01/18 06/03/18 42±0.82 March 1st week 3rd week of March 4th week of March Numbers represent means ± one standard error (SE) of the mean ESWARAPPA AND SOMASHEKAR S411 flower opening was more in wild S. cumini at Ponnampet and wild S. cumini at GKVK location (19/3) compared to cultivated varieties at GKVK location th (Table 1). The variation in the initiation of inflores- cence and the number of days taken for first flower opening is attributed to variation in varietal/species (18/3) 8 trait in a particular location. Flowering of jamun ini- th tiated in first week of March and continues up to the end of April with total flowering duration is around four weeks (Bajpai and Chaturvedi, 1985; Tarai et

al., 2006). (17/3) 7 The visual observation made on number of floral th buds opened in all the branches of wild and culti- vated varieties of S. cumini starting from their pe- riod of first flower opening revealed that the floral buds of cultivated variety GKVK-1 started flower- (16/3) 6 th ing from 3rdweek of February, reached 50 and 100 percent flowering during 2ndand 3rdweek of March. The opening of floral buds in wild S. cumini at Ponnampet, wild S. cumini at GKVK and cultivated (15/3) 5 varieties, GKVK-2, K-45 and N-20 were started from th 12.67 (25)12.67 14.67 (28.95) 12.33 (24.34) 4.00 (7.89) 1.33 (2.63)

1st week of March, reached 50 and 100 percent flow- 10.67 (26.45) 11.67 (28.93) 8.67 (21.49) 4.00 (9.92) 1.67 (4.13) ering during 4thMarch with a total of four week flowering duration (Table 1). On the contrary to

these findings Solomon et al. (2014) while studying (14/3) 4 rd the reproductive ecology of syzygium alternifolium at Ponnampet and GKVKduring 2018 recorded the floral bud initiation in late March while flowering occurs during mid - April to mid –

Mayand the flowering lasted in 21 days. S. cumini

The flower opening pattern of wild and culti- (13/3) 3 nd vated varieties of S. cumini was studied in randomly selected four tagged inflorescence having matured floral buds. The mean numbers of floral -- 2.00(2.61) 2.33(2.63) 6.00 (7.83) 9.33 (10.53) 13.67 (17.83) 17.00 (22.17) 16.33 (18.42) 24.67 (32.17) 19.6 (22.18) 8.33 (10.87) 28.00 (31.58) 5.00 (6.52) 7.00 (7.89) 6.00 (6.77) buds present in each inflorescence was counted and - 1.67(2.48) 3.67 (5.45) 12.33 (18.32) 17.67 (26.24) 22.67 (33.66) 6.33 (9.41) 3.00 (4.46) (12/3) 2 were observed daily until all floral buds opened st completely. The results revealed that the numbers of

floral buds present in the inflorescence of cultivated 67 variety, GKVK-2 were maximum (88.67±2.16) fal- lowed by GKVK-1(76.67±2.58), wild S. cumini at Ponnampet (67.33±0.82), wild S. cumini at GKVK (62.0±1.82), N-20(50.67±1.43) and the lowest was recorded in K-45(40.33±1.47). These findings are supported by Saurabh Singh et al. (2019) while studying floral biology, fruit set and fruit drop of different genotypes of jamun (Syzygium cumini L.) 11/03/18 62.0 0 ± 1.82 - - 5.0 (8.06) 10.67 (17.20) 15.33 (24.73) 22.33 (36.02) 5.33 (8.60) 3.33 (5.38) 11/03/18 67.33 ± 0.82 reported a maximum of 26 flowers per inflorescence in S-9 and a minimum of 16 flowers per inflores- cence in S-7 genotypes. The daily observation on Flower opening pattern of wild and cultivated varieties number of floral buds opened per inflorescence in- S. cumini dicated that, none of the floral buds started opening S. cumini st (At GKVK) GKVK - 1GKVK - 2K - 45 11/03/18 11/03/18 76.67 ± 2,58 88.67 ± 2.16 11/03/18 40.33 ± 1.47 - - 3.67 (9.09) N - 20 11/03/18 50.67 ± 1.43 - - 5.67 (11.18) (At Ponnampet) Wild Table 2. Wild/cultivated inflorescenceWild floral buds/ Date of 1 Avg. no. ofFigures in parentheses are percentage. Numbers represent means ± one standard error (SE) of the mean Flower opening pattern on different days after inflorescence tagged (%) on the 1 day after inflorescence tagging. Only, the varieties tagged inflorescence S412 Eco. Env. & Cons. 26 (November Suppl. Issue) : 2020

floral buds from wildS. cumini at Ponnampet, culti- of floral bud opening is attributed to variation in the vated variety, GKVK-1 and GKVK-2 were opened number of floral buds present among the inflores- on 2nd day after inflorescence tagging with per cent cence of wild and cultivated varieties of S. cumini. flower opening ranged from 2.48 to 2.63. In addi- Anju Bajpai et al. (2012) in their studies on reproduc- tion, the floral buds from wild S. cumini at GKVK, tive phenology, floral biology and pollination in S. cultivated varieties, K-45 and N-20 started opening cumini have made similar observations where in, from 3rd day after inflorescence tagging. The num- the number of flowers opening each day was ini- ber of floral buds opened were found increasedin K- tially less, but increased rapidly, with a peak of 45(28.93%), N-20 (28.95%) upto 5th day and in flowering for a fortnight which subsequently de- wildS. Cumini at Ponnaampet (33.66%), wild S. clined rapidly. cumini at GKVK (36.02%), cultivated varieties, Ten fully opened flowers were picked randomly GKVK-1 (32.17%) and GKVK-2(31.58%) upto 6th day from selected inflorescence of wild and cultivated after inflorescence tagging followed by a declining varieties of S. cumini and their architectural charac- trend. The floral buds present in all the inflores- teristics were studied in the laboratory (Cruden, cences were opened completely by 8th day 1977; Pias and Guitian, 2001; Griffin and Barrett, afterinflorescence tagging. It is cleared that, once 2002). The results revealed that the inflorescence is theopening floral buds started in an inflorescence, it terminal and axiliary having hermaphrodite, is continued upto six days in wild S. cumini at creamish white flowers, length ranged from GKVK, K-45, and N-20 and up to seven days in wild 15.89±0.82 (GKVK-1) to 16.09±0.03 mm (wild S. cumini at Ponnampet, GKVK-1 and GKVK-2 S.cumini at GKVK), width ranged from 1.98±0.05 (Table 2 and Figure 1). The variation in the duration (wild S. cumini at Ponnampet) to 2.05±0.04 mm (N-

Fig. 1. Flower opening pattern observed in wild and cultivated varieties of S.cumini at GKVK and Ponnampet

Table 3. Floral architecture of wild and cultivated varieties of S. cumini at ponnampet and GKVK during 2018 Wild/ Flower Flower No. of No.of No. of length of length No. of Flower cultivated length width sepals/ petals/ stamens/ stamen of carpel ovules/ longevity varieties (mm) (mm) flower flower flower (mm) (mm) flower (days) Wild S. cumini 16.04±0.79 1.98±0.05 5.00 5.00 67.67±2.28 5.07±0.06 6.05±0.02 8 3 (At Ponnampet) Wild S. cumini 16.09±0.03 1.99±0.06 5.00 5.00 68.33±1.56 5.23±0.05 6.04±0.05 8 3 (At GKVK) GKVK-1 15.89±0.82 2.01±0.02 5.00 5.00 64.63±1.63 5.20±0.08 6.15±0.05 8 3 GKVK-2 16.01±0.95 2.03±0.03 5.00 5.00 63.66±1.97 5.10±0.04 6.20±0.04 8 3 K-45 15.97±0.81 1.99±0.08 5.00 5.00 63.66±2.48 5.15±0.05 6.05±0.03 8 3 N-20 16.07±0.82 2.05±0.04 5.00 5.00 62.33±2.64 5.25±0.03 6.28±0.03 8 3 Numbers represent means ± one standard error (SE) of the mean ESWARAPPA AND SOMASHEKAR S413

20). Solomon Raju et al. (2014), while studying the tion by external agents for proper fruit set and fruit reproductive ecology of Syzygium alternifolium ob- yield. served that, the flowers borne on terminal and axil- lary cymes with divaricating branches and each in- Conclusion florescence consisted of 22-53 pedicellate flowers, creamy white, 16 mm long and 2 mm wide. The In the present study the number of days required number of sepals and petals were five in studied from initiation of inflorescence inwild and culti- wild and cultivated varieties. The number of sta- vated varieties of S. cumini up to first flower open- mens ranged from 62.33±2.64 (N-20) to 68.33±1.56 ing ranged from 40±0.82 (K-45 variety at GKVK) to (wild S. cumini at GKVK). The length of the stamens 46±0.82(wild S. cumini at Ponnampet). The initiation ranged from 5.10±0.04 (GKVK-2) to 5.25±0.03 mm of flowering, 50 and 100 per cent flowering was ob- (N-20) and the length of the carpel ranged from served in the 1st, 3rd and 4th week of March in wild 6.04±0.05 (wild S. cumini at GKVK) to 6.28±0.03 mm and cultivated varieties of S. cumini, with the excep- (N-20). The ovary is inferior and the whorls of flow- tion of GKVK-1. The floral bud opening pattern in ers are attached at the apex. The ovary is bilocular, an inflorescence revealed that, once the floral buds bicarpellary and syncarpous. The gynobasic style is started opening, it continued up to six days inwild arises between the ovary lobes with simple stigma. S. cumini at GKVK, K-45, N-20 and up to seven The stigma and style was born in the center of the days inwild S. cumini at Ponnampet, GKVK-1 and cup of the flower. In all fully opened flowers, the GKVK-2. This study indicated a staggered pattern stigma is found extended out of circular band of the of flowers openingin the inflorescence for the period stamens and the pollen grains were spherical in of one week. Eight ovules per flower were observed shape, tricolporate with mean diameter ranged with longevity of flower lasting for three days. The from 12 to 18 µm among the wild and cultivated va- wilting of flower and dropping of stamens were rieties of S. cumini. There were eight ovulesper observed at 4th day after flower opening. The archi- flower of studied wild and cultivated varieties of S. tectural characteristics of the flowers such as flower cumini (Table 3). Solomon Raju et al. (2014) in S. colour, numbers of sepals, petals, ovules and flower alternifolium also stated that the ovary is bicarpellary longevity revealed no differences among the wild S. and bilocular syncarpous contains 21 - 38 ovules on cumini and cultivated varieties. axile placentation. The style tipped with semi - wet simple stigma, arises from the centre of the cup and Acknowledgements stretches out of the stamen ring by 2 - 3 mm. Further the studies on ovule abortion in S. cumini made by The authors are thankful to College of Forestry Arathi et al. (1996) and Krishnamurthy et al. (1997) Ponnampet, Regional Horticultural Research and revealed that, the resource uptake is inhibited by the Extension Centre, College of Horticulture; UHS sub subordinate seeds and hence the usually de- campus andthe Departmentof Apiculture, UAS, velops only 1 to 30 ovules to maturity. The longev- GKVK, Bengaluru for extending research facility ity of flower was three days, dropping of stamens and technical support. and wilting of flower was observed on the 4th day of flower opening in wild as well as in cultivated vari- References eties of S. cumini. On the contrary to the present findings, Solomon Raju et al. (2014) stated that the Arathi, H.S., Ganeshaiah, K.N.,Umashaanker, R. and stamens fell on the second day of flower life, while Hegde, S.G. 1996. Factors affecting embryo abortion the other parts remained intact for five days, if not in Syzygium cumini (L) Skeels (Myrtaceae). Interna- pollinated. In pollinated flower, the calyx cup was tional Journal of Plant Sciences. 157 : 49-52. persistent and the fruit emerged out when fully Ayyanar, M. and Subash-Babu, P. 2012. Syzygium cumini grown. Overall, the floral architectural results indi- (L.) Skeels: A review of its phytochemical constitu- ents and traditional uses. Asian Pacific Journal of cated that not much variation were observed among Tropical Biomedicine. 2(3) : 240-246. numbers of sepals, petals, ovules, flower colour and Bajpai, P. N. and Chaturvedi, O. P. 1985. Fruits of India: flower longevity. The difference in the length of sta- Tropical and Subtropical. Naya Prokash Publishers. men and carpel and also the extension of stigma out Calcutta. 586 p. of the stamens indicated the need of cross pollina- Bajpai, A., Singh, A.K. and Ravishankar, H. 2012. Repro- S414 Eco. Env. & Cons. 26 (November Suppl. Issue) : 2020

ductive phenology, flower biology and pollination near Eurosiberian- Mediterranean border in the NW in jamun (Syzygium cumini L.) Indian Journal of Hor- Iberian peninsula. Flora. 196 (6) : 475-482. ticulture. 69(3) : 416-419. Reddy, K.N. and Reddy, C.S. 2008. First Red list of medici- Chaudhary, B. and Mukhopadhyay, K. 2012. Syzygium nal plants of Andhra Pradesh, India-Conservation cumini (L.) Skeels: A potential source of assessment and management planning. nutraceuticals. International Journal of Pharmacy and Ethnobotonical Leaflets. 12 : 103-107. Biological Sciences. 2(1) : 46-53. Swami, S.B., Thakor, N.S.J., Patil, M.M. and Haldankar, Chongthanallaylaydevi, G.S.K. Swamy and Nagesh Naik. P.M. 2012. Jamun (Syzygium cumini (L.): A Review 2016. Studies on flowering and fruit characters of of Its Food and Medicinal Uses. Food and Nutrition. jamun genotypes (Syzygium cumini Skeels). Bio- 3(1) : 1100-1117. sciences Biotechnology Research Asia. 3(4) : 2085-2088. Solomon Raju, A. J., Radha Krishna, J. and Hareesh Cruden, R.W. 1977. Pollen-Ovule Ratios: A Conservative Chandra, P. 2014. Reproductive ecology of syzygium Indicator of Breeding Systems in Flowering Plants. alternifolium (Myrtaceae), An endamic and endan- Evolution. 31(1) : 32-46. gered tropical tree species in the southern eastern Griffin, S.R. and Barrett, S.C.H. 2002. Factors affecting low ghats of India. Journal of Threatened Taxa / seed: ovule ratios in a spring woodland herb, Tril- www.threarenedtaxa.org/26 August 2014/6(9) : 6153 – lium grandiflorum (Melanthiaceae). International Jour- 6171. nal of Plant Science. 163 (4) : 581-590. Tarai, R.K., Kundu, S., Ghosh, B. and Mitra, S. 2006. Per- Krishna murthy, K.S., Umashaanker, R. and Ganeshaiah, formance of some minor fruits in west Bengal. Pro- K.N. 1997. Seed abortion in an animal dispersed ceedings of national symposium on production , utiliza- species Syzygium cumini (L) Skeels (Myrtaceae):The tion and export of underutilized fruits with commercial chemical basis. Current Science. 73 : 869-873. potentialities, 2-24 November 2006, Bibhan Chandra Pias, B. and Guitian, P. 2001. Flowering phenology and Krishi Viswavidyalaya, West Bengal. pp. 79-82. pollen-to ovule ratio in coastal dune communities