The International Journal of Plant Reproductive Biology
(Indexed by CABI)
ISSN Print : 0975-4296; ISSN Online : 2249-7390
)
 
Volume-4, Number-1, January 2012
 

A Unique Mode of Mechanical Autogamy in Phalaenopsis taenialis (Lindl.) E.A. Christensen & Pradhan (Orchidaceae)

S. K. Chaturvedi
Department of Botany, Nagaland University, Lumami-798 627, Nagaland (India)

e-mail:
sunchat1@rediffmail.com
Received : 11.08.2011; Revised : 02.10.2011; Accepted : 15.10.2011; Published on line : 20.10.2011

  ABSTRACT

A unique mechanism of mechanical self pollination (autogamy) has been reported in Phalaenopsis taenialis (Lindl.) E.A. Christensen & Pradhan growing at Tuensang and Mokokchung districts of Nagaland (North-East India). Indirect autogamy due to the 360 curving of stipe of pollinarium has been described for the first time. Similar mechanism of self pollination has been described by Liu et al (2006) in Holcoglossum amesianum. Around 30% of the flowers produce fruits due to successful self-pollination. No biotic visitor / pollinator have ever been observed on the flowers during anthesis.

Keywords : Phalaenopsis taenialis (Lindl.), mechanical autogamy, curving of stipe, Tuensang and Mokokchung (Nagaland).

 
  Pollination Biology of Stictocardia tiliifolia (Desr.) Hall. f. (Convolvulaceae)

Aswani K & M Sabu*
Taxonomy Division, Department of Botany, University of Calicut-673 635, Kerala, India

*e-mail:
msabu9@gmail.com
Received : 16.11.2011; Revised: 28.12.2011; Accepted: 30.12.2011; Published on line: 2.2.2012

  ABSTRACT

The pollination biology of Stictocardia tiliifolia (Desr.) Hall. f. (Convolvulaceae), a beautiful ornamental climber was investigated. It flowers between December to April with the peak blooming period in February. During the peak flowering period, nearly 5060 flowers/plant bloom every day. Flowers open between 5.30 6.30 am and the life span of an individual flower is 24 h. Anther dehisce 8-9 h before anthesis, showing the protandrous nature of the flower and at the time of anthesis, 643% pollen grains were viable. Stigma becomes receptive at the time of anthesis. Nectar is secreted by a hypogynous disc. Flowers are visited by several insects and birds. However, Apis dorsata, Trigona iridipennis, Katydid [Letana species (female)], Nectarinia zeylonica and N. asiatica are the main pollinators and Katydid as a pollinator has been reported for the first time. Pollen grains in spite of landing on the receptive surface of the stigma fail to germinate indicating self-incompatible nature of the plant which remains fruitless. The plants from which the pollen was used for cross pollination seems to be clonal sisters and genetically alike.

Keywords : Convolvulaceae, Katydid, Pollination biology, Sporophytic incompatibility, Stictocardia tiliifolia.

 
  Fruit and seed-set in Vicia sativa L., the common vetch.

Uzma Hamal & Namrata Sharma*
Department of Botany, University of Jammu, Jammu-180006

*e-mail : phyllanthus@rediffmail.com
Received : 5.1.2012; Revised : 20.01.2012; Accepted : 24.1.2012

  ABSTRACT

Vicia sativa, the common vetch, is an important forage crop species cultivated in many countries (Hanelt & Mettin, 1989). The species forms a natural patchy population in the area of study located in Jammu province, J&K state, India. This seemingly outcrossed species revealed vivid anomalies in fruit set in plants growing wild from those that were kept as control. The communication identifies patchy distribution, competition for pollinators and herbivory as the factors responsible for the same.

Keywords : fruit and seed set, herbivory, patchy distribution, Vicia sativa

 
 

Studies on the pollen-pistil interaction and biochemical analysis of incompatibility in Ananas comosus var. Comosus (pineapple) and Ananas nanus (Bromeliaceae)

P. K. Brijithkumar, R.S. Nisha Raj, Femy K. Haneef & P. M. Radhamany*
Department of Botany, University of Kerala, Kariavattom,
Thiruvananthapuram, Kerala, India-695581
*e-mail : radhamany_m@rediffmail.com
Received : 6.12.2011; Revised : 31.12.2011

  ABSTRACT

Sexual reproduction is essential for maintaining the species identity and permitting a reasonable degree of infraspecific genetic variability. Ananas comosus var. comosus (pineapple) and Ananas nanus (Bromeliaceae) is known to lack seed formation due to self-incompatibility. Crop improvement through conventional breeding methods is not possible in Ananas due to the occurrence of self-incompatibility. In order to study the pollen tube growth and behaviour, and biochemical changes of pistil after inter- and intraspecific pollinations, analysis of pollen viability, controlled pollination experiments and protein profiles of self-pollinated and unpollinated pistilswere analysed. Estimation of pollen viability using FCR test (80-90%), in vitro (65.23- 3. 60) and in vivo pollen germination showed viability in both the species. During self as well as cross-pollinations within and between the species, pollen tube growth inhibition was observed on the surface of the stigma. Electrophoretic analysis of proteins from the unpollinated and self-pollinated pistils showed that an additional protein band at 56 kDa was present in pollinated pistil. Significant variation in the protein profile between the two species was observed. The study concluded that self-pollination induced a specific protein in both the species, which may responsible for incompatible interaction in Ananas.

Keywords : Ananas, Fluorescence, incompatibility, FCR test, Electrophoresis

 
 

Polyethylene glycol and Polyamines promote Pollen germination and Tube growth in Azadirachta indica (Meliaceae)

Vikas,Vineet K. Singh & Rajesh Tandon*
Department of Botany, University of Delhi, Delhi-110007, India
*e-mail :
tandon.raj@gmail.com
Received : 01.09.2011 Revised : 18.1.2012; Accepted & Published online : 1.2.2012

  ABSTRACT

A novel in vitro pollen germination medium has been standardized for neem (Azadirachta indica A. Juss.) by optimizing the concentration of Brewbaker & Kwack's (BK) components in combination with different concentrations of sucrose and polyethylene glycol (PEG). Fresh pollen grains showed nearly 70 %fertility and viability. Pollen grains failed to germinate in BK medium alone and those in BK medium supplemented with various concentrations of PEG MW10, 000. Addition of 30% sucrose to BK medium supplemented with 20% PEG MW20, 000 induced nearly 70% germination and produced 247.8 27 μm long pollen tubes. Pollen germination and tube growth could be significantly enhanced by the addition of polyamines. Among the three -4 polyamines (putrescine, spermine or spermidine) tested, putrescine gave the best response and at 10 M, increased the germination response to 95% and tube growth to 281.222.0 μm. As neem tree is known to be an obligate outbreeder, formulation of a reliable pollen germination protocol would be beneficial in screening pollen parents for germinability and for checking the quality of pollen samples during long-term storage.

Keywords : in vitro pollen germination, neem, PEG, polyamines

 
  Reproductive Biology of Santalum album L.

Seema Chauhan
Department of Botany, School of Life Sciences, Dr. B.R. Ambedkar University, Agra-282002, India

e-mail :
semchau@gmail.com
Received : 18.08.2011; Revised : 12.09.2011; Accepted & Published on line : 17.10.2011

  ABSTRACT

Santalum album L. (Santalaceae) is an evergreen obligate semi-parasitic tree. It flowers during the months of July to October. Large number of small flowers are arranged in terminal or axillary clusters. Flowers are pink, but after fertilization they turn scarlet red. They are bisexual, actinomorphic and epigynous. As the perianth is not differentiated into calyx and corolla, there are 4-6 tepals. The number of stamens also varies in accordance to the number of tepals. Flowers open at 0630 h, anthers dehisce between 0700-0830 h and stigma becomes receptive 24-48 h after the opening of flowers. Pollen grains of 202 μm diameter were 3-porate, sub-prolate. An anther produced 285 25 pollen grains and per flower there were 1175 30 pollen. Pollen fertility as tested by various methods ranged between 60-82%. There was only one ovule/flower and the pollen-ovule ratio was 1175:1. Small bees (Melipona spp.), baron (Euthalia aconthea; Order: Lepidoptera; Family: Nymphalidae) and hower flies (Ornida obesa; Order: Diptera; Family: Syrphidae), and red ants (Trathile hepileae), visited the flower but pollination was brought about by Melipona and baron, while others were merely nectar robbers. S. album is selfincompatible as the bagged flowers failed to produce fruits. In open pollination the fruit-set varied between 5-20% depending upon the place. The fruit-set was 2-5 and 25-30% by geitonogamy and xenogamy, respectively. These results and pollen-ovule ratio indicate the tree is predominantly out-breeding exhibiting facultative xenogamy.

Keywords : Santalum album, floral biology and pollination

 

Influence of bee attractants on pollination and yield parameters in Guava (Psidium guajava L.)

Anita M.*, V. Sivaram & K. V. Jayaramappa
Laboratory of Biodiversity and Apiculture, Department of Botany, Bangalore University, Bangalore.

*e-mail : anitam35@yahoo.com
Received : 09.12.2011; Revised : 19.1.2012; Accepted : 22.1.2012

  ABSTRACT

The use of bee attractants, Bee-Q, Bee Scent and Fruit Boost in the pollination of guava was evaluated. The bee visitation on guava flowers was made for a week, followed by estimation of quantitative and qualitative parameters in fruits. The different concentrations of bee attractants were evaluated to understand the honeybee visitation pattern of target crop for improving pollination efficiency. The observations indicate that the best mean foraging time on guava flowers was observed at 1000 hours (6.78) followed by 1200 hours (4.89) and 1400 hours st (3.78) . Bee scent @ 1.5 ml/l (15.67) was the most effective bee attractant in increasing bee visitation on the 1 day of spray in guava. Bee scent @ 2 ml/l (14.00) significantly attracted higher number of bee foragers than the control in guava plots. In addition, the plants sprayed with bee attractants significantly enhanced the length, diameter, and weight of fruits and total soluble sugars in guava. The present investigation suggests that the bee attractants increase marginal percentage of bee visitation and fruit parameters in guava.

Keywords : Psidium guajava, bee-attractants, honeybee, pollination, yield parameters.

 
 

Assessment of Honey Plant Resources through Pollen Analysis in Coorg Honeys of Karnataka State

Agnes Farkas* & Zsuzsanna Orosz-Kovacs
Department of Pharmacognosy, Medical School, University of Pecs, Hungary
Deparment of Plant Systematics and Geobotany, Institute of Biology, Faculty of Sciences, University of Pecs,Hungary

*e-mail : farkasa@gamma.ttk.pte.hu
  ABSTRACT

Pollen analysis of honey samples collected from Coorg district of Karnataka state was undertaken to gather information regarding the bee forage plants and to determine the prevailing bee-plant relationship. In the present investigation, 20 honey samples were collected from Apis cerana and Apis dorsata colonies during January 2010 to April 2011 from bee hives located at 14 locations of Coorg district. A total of 91 pollen types belonging to 42 families were identified. The dominant pollen types were Coffea sp., Cocos nucifera, Aster sp., Scheffleria sp., Syzygium sp., Terminalia sp., Brassica sp., Croton sp., Oryza sativa, etc. Among the pollen types observed, 53.84% were tree species and the most preferred. The highest contribution for nectar and pollen source for honeybee in the study area belonged to the Fabaceae and Asteraceae. This paper discusses the honey plant resources, potentialities for commercial beekeeping in Coorg district and also the importance of honeybees in the forest and agriculture ecosystem.

Keywords : Beekeeping, honeybees, honey plants, pollen analysis

 
 

Morphological and Reproductive variations within the Boucerosia umbellata complex (Family: Apocynaceae; Subfamily: Asclepiadoideae) in Southern India

S. Karuppusamy , A. Ugraiah and T. Pullaiah
1Department of Botany, The Madura College (Autonomous), Madurai 625 011, Tamil Nadu, India.
2Department of Botany, Sri Krishnadevaraya University, Anantapur 515 003, Andhra Pradesh, India.

e-mail:
ksamytaxonomy@gmail.com; pullaiah.thammineni@gmail.com
Received : 20.12.2011 Revised : 4.2.2012 Accepted : 8.2.2012

  ABSTRACT

Boucerosia umbellata sensu lato is a succulent xerophytic leafless herb belonging to the family Apocynaceae (Stapeliae). The taxonomic status of this in India is still dubious due to the great variability in colour and shape of the flower, number of flowers in inflorescence, shape of the corona, hairiness pattern on corolla lobes and fruit development pattern. Morphological and reproductive variation was investigated in 16 different sites of southern India with about 180 individuals. The collected specimens represented the B. umbellata complex, including two synonymized species B. campanulata and B. lasiantha. Based on qualitative macro- and micro- morphological and reproductive characters, the B. umbellata complex can be divided into 5 different reproductive groups. They can be distinguished by floral traits, pollinator interaction and fruit developmental pattern. The investigation supported to retain a few sub-group into species rank such as B. lasiantha.

tKeywords : Reproductive variations; Boucerosia umbellata; Stapeliae; fruit development.

 
 

Development, Structure and Viability of Embryo in Schima khasiana Dyer and S. wallichii (DC.) Korth. (Theaceae)

Sanjiban Goswami & Arun K. Pandey
1
Department of Botany, St. Edmunds College, Shillong-793003, Meghalaya, India
2
Department of Botany, University of Delhi, Delhi-110007, India

*e-mail:
arunpandey79@gmail.com
Received : 18.1.2012; Revised : 31.1.2012; Accepted : 12.2.2012

  ABSTRACT

Embryo development in Schima khasiana and S. wallichii (family Theaceae) has been undertaken. In S. khasiana, the time between fertilization and the zygote division varied between 12 to 15 months whereas in S. wallichii the division of zygote took only about 12 weeks after fertilization. The globular pro-embryo developed in 14 to 16 months in S. khasiana, while, in S. wallichiii it took only 14-18 weeks. The embryos have long suspensors. The differentiation of cotyledons occurred in 14-17 months after fertilization in S. khasiana, whereas in S. wallichii it took 22 weeks. The viability of embryo was 92% in S. wallichii as compared to 32% in S. khasiana. Fruit, a loculicidal capsule, drops prematurely in both the species at late globular or early heartshaped stage of embryo. In both the species, controlled pollination showed that fruits from self- ollinated flowers have a greater tendency to drop prematurely than from fruits produced from cross-pollinated flowers.

Keywords : Schima, Theaceae, embryo, viability

 
 

Expression of Anther-Tapetum Specific Genes-Bcp1 and callase in Chemically Induced Male Sterile Plants of Brassica juncea (L.) Czern & Coss

S.V.S. Chauhan *, H.K. Gupta , Vandana Singh , Ram Dass & V.M. Katoch
1
Academy of Life Sciences, 8/13 I Kaushalpur Bye Pass Road, Agrs-282005, India
2
SERC Division, Department of Science & Technology, New Delhi-110016, India
3National Institute of Leprosy & other Microbial Diseases, Agra-282001, India
4 Director General, Indian Council of Medical Research, Ansari Nagar, New Delhi-11010,
India
*e-mail: svs350rediffmail.com; svsc16@gmail.com
Received : 16.08.2011; Revised : 12.10.2011; Accepted & Published on line : 15.12.2011

  ABSTRACT

The tapetal cells, the innermost layer of the anther wall, surrounds the microspores during their development and in the ms mutants anther ontogeny is blocked at different end points during microsporogenesis leading to male sterility. The gene expression profiles of the microspore/pollen and the sporophytic tapetum in several male fertile as well as genic and cytoplasmic male sterile plants have received considerable interest. However, little attention has been paid to understand the mode of anther specific genes in chemically treated male sterile plants. Present study was undertaken to study the expression of anther-tapetum specific genes Bcp1 and callase in the anthers of Brassica juncea plants treated with some chemical hybridizing agents (ethrel, gibberellic acid, maleic hydrazide, benzotriazole, azetidine 3-carboxylate and detergent surf excel). Faint or intense signals of both the genes (Bcp1 & callase) were observed in the dot blot analysis of anthers of CHAs treated male sterile plants. The real-time PCR analysis exhibited that Bcp1 gene in the anthers of male sterile plants treated with gibberellic acid and bezotriazole remained suppressed, while in the anthers of azetidine 3-carboxylate, ethrel, surf excels and maleic hydrazide treated male sterile plants it was over expressed. Similarly, callase gene became suppressed in the anthers of surf excel treated plants, while in the anthers of gibberellic acid, bezotrizole and ethrel treated plants it was over expressed.

Keywords : Brassica juncea, chemical hybridizing agents, dot-blot, real-time PCR, Bcp1 and callase gene

 
 

Effect of zinc, boron and manganese on reproductive parameters in hydroponically grown Capsicum annuum L.

Joyti Rathi & Anita Rana*
Department of Botany, School of Life Sciences, Dr. B.R. Ambedkar University, Agra-282002, India

*e-mail: anita_rana21@rediffmail.com
Received : 21.10. 2011; Revised : 30.12. 2011; Accepted : 12.2.2012

  ABSTRACT

Impact of deficiency of boron, zinc and manganese separately and in various combinations on reproductive parameters in hydroponically grown Capsicum annuum L. was studied. The plants grown in nutrient media deficient in B, Mn and Zn singly or in different combinations exhibited significant reduction in number of flowers, fruits, fruit size and weight and total yield. The flowering in such plants was also significantly delayed and plants grown in the nutrient medium without boron failed to produce flowers.

 

 
 

Factors affecting Reproductive Success in Jacaranda mimosifolia D. Don. (Bignoniaceae)

Anita Rana* & Seema Chauhan**
Department of Botany, School of Life Sciences, Dr. B.R. Ambedkar University, Agra-282002, India

*e-mail: anita_rana21@rediffmail.com
**e-mail: semchau@gmail.com
Received : 29.11.2011; Revised : 12.12.2011; Accepted : 10.01.2012

  ABSTRACT

Present investigation deals with the factors that affect fruit formation in Jacaranda mimosifolia (Bignoniaceae) at Agra, Uttar Pradesh, India. The trees flowers profusely between February-May. In February and March 155 fruits/plant (n=15) developed and in subsequent months (April and May), fruit formation declined to only 52 fruits/plant. Reduction in natural fecundity was associated with several factors particularly, rise in temperature. With the commencement of flowering in Februray (20-25C), the plants exhibited 865% pollen fertility. With the increase in temperature during March, April and May (35-45C), the plants exhibited a gradual decline in pollen fertility and in May (38-40C) it was only 155%. During this period a large number of young floral buds, corolla with epipetalous stamens, unfertilized and fertilized pistils were abscised. Flowers opened between 0630-0700 h, and anthesis lasted 122 h. Anthers dehisce soon after the opening of the corolla tube but stigmatic lobes remained closed and opened between 1300-1400 h. Melipona spp. were the frequent visitors and take away both nectar and  ollen. They start visiting the flowers soon after the anthesis and continued till the end of anthesis at 1400-1800 h, but by this time the pollen vaibility declined to 505%. The frequency of the visitors also declined and they continued to visit in the afternoon and transfer enough pollen grains on the stigmatic surface to contribute the formation of 152 fruits/plant Glandular and non-glandular trichomes (capitate and noncapitate) observed on different floral parts (calyx, corolla, staminal filament and well developed staminode) secrete nectar, but with the rise in temperature, the nectar secretion also declines. There was no fruit set in bagged flower indicating its self-incompatible nature of the tree. The emasculated bagged flowers on pollinating with the pollen from the flowers of the same plant (geitonogamy) or pollinating with the pollen from the flowers of different plants (xenogamy) produced fruits. It is concluded that high temperature cause marked reduction in pollen fertility, quantity of nectar, number of floral visitors; enhanced abscission of floral buds and unfertilized and fertilized pistils were the main constraints in the reproductive success of Jacaranda mimosifolia plants growing at Agra.

Keywords : Jacaranda mimosifolia, Bignoniaceae, fruit formation, pollen viability, staminode, abscission, trichomes.

 
  Phenological events in Haplophragma adenophyllum (Wall) P. Dop.

Reenu Gupta & Anita Rana*
Department of Botany, School of Life Sciences, Dr. B.R. Ambedkar University, Agra-282002, India

*e-mail: anita_rana21@rediffmail.com
Received : 07.08.2011; Published online : 17.08.2011

  ABSTRACT

Haplophragma adenophyllum (Bignoniaceae) a handsome tree of 30-50 feet is planted in the gardens and avenues for its beautiful flowers and foliage. The stem is woody in the lower portion and often cylindrical, solid in upper portion of the plant. Leaves are large, 36-45 cm long, pinnate, the leaflets are elliptical, entire, acute, glabrous above and pubescent beneath. Leaf fall occurs throughout the year and maximum during February to April. Leaf renewal takes place simultaneously. It flowers between the second week of June (28-42C) to second week of November (12-28C) and optimum flowering takes place between the months of August (25-35 C) to October (19.2-34C). There are 35-41 floral buds/terminal racemose panicle inflorescences. The flowers are yellowish-brown in colour. They are large (11.8 0.17 cm long), complete, zygomorphic, hermaphrodite, hypogynous, sub-sessile and bilabiate personate in shape. Calyx consists of four gamosepalous sepals (4.140.2 cm long), campanulate, valvate and brown in colour. Corolla consists of five gamopetalous, imbricate aestivation and bilabiate-personate 7.150.38 cm long petals. The androecium consists of four fertile didynamous, dithecous and introse stamens, while the fifth one is represented by a staminode. The anther of large stamen is 0.94 0.06 cm with 5.080.1 cm long filament, while the anther of short stamen is 0.8 0.06 cm long with 4.120.06 cm long filament. The gynoceium is bicarpellary and syncarpous with superior, bilocular 1.740.19 cm long ovary. There are many ovules in each locules on axile placentation. The style is terminal and 4.670.24 cm long. The stigma is bifid and wet and sensitive as both the lobes close down by different type of external stimuli, but reopen after some time. However, close down permanently on both geitinogamy and xenogamy. Flowers open between 2000 to 2145 h and anther dehisce between 2115 to 2145 h and stigma becomes receptive at 2145 to 2230 h. There are 1187341189 pollen/anther and 472620 3421 pollen/flower. There are 5958 ovules/ovary and the pollenovule ratio is 79.32-1. The fruits are long (71.372.1 cm), cylindrical, curved and bivalve. Fruiting  starts in the second week of August and continues till the last week of November. Maximum number of fruits developed in October. Fruits start maturing in October and dehisce longitudinally to disperse the compressed and winged seeds in the months of December and January. There are 5920 seeds/fruit.

Keywords : Haplophragma adenophyl lum, Bignoniaceae, phenology.

 
  Phenology in Kigelia pinnata (Jacq.) DC.

Raman Kumar* & Veenu Kaul
Department of Botany, University of Jammu, Jammu (J&K) - 180 006

*e-mail:
ramankumar1313@gmail.com
Received on : 30.07.2011; Published online : 17.08.2011

  ABSTRACT
Kigelia pinnata (Jacq.) DC. (Bignoniaceae) a native to Africa is commonly known as sausage tree due to its large gourd-like fruits, In India, it is chiefly grown for ornamental purposes, but it is of great medicinal and ethnobotanical importance. Many chemical compounds e.g. napthoquinones and iridoids isolated from its different parts possess antifungal, antibacterial and antiprotozoal properties. The present communication describes some of the phenological events in this tree species. Present observations have been recorded on the trees of Kigelia pinnata growing at two sites separated by 1 km in the campus of University of Jammu (J & K, India). Both the sites consisted of 49 trees (site 1 has 31 and site 2, 18 trees). Studies were conducted on these trees between February and October during 2005, 2006 and 2007. Data were collected largely from site 1  due to easy accessibility of inflorescences. Trees are perennial, medium to large sized, fast growing  having a short trunk, with a crown of dense branches. Leaves are imparipinnately compound having 7-9 leaflets which are rough in texture. New leaves differentiate twice in a year, first in March when flowering starts and then in August- September. Inflorescence is a thyrse which is differentiated into main and lateral axes. Differentiation and blooming of flowers occurs in the first and last week of February, respectively. Flowers keep differentiating till October. Majority of the trees are in peak flowering during April and May which declines in subsequent months. An individual flower of K. pinnata is deep red, large sized, hermaphrodite, zygomorphic and herkogamous. Flowers are pentamerous bearing five sepals and five petals. Anthesis initiates around 1930 h and by 2030 h, the flowers open fully. The about-to-open flower bud is characterized by the expansion of corolla and subsequent loosening and withdrawl of corolla tube from the calyx. At this hour, intense unpleasant odour is emitted by the flowers. The androecium comprises of five epipetalous stamens; four fertile, didynamous and one sterile. Anthers start dehiscing prior to anthesis, in the afternoon and around 1600 h dehiscence slits are formed throughout the length of the anthers. Thus, by the time flowers open completely, the anthers are already dehisced. However, their contents are not emptied till then. The gynoecium consists of a bicarpellary, syncarpous pistil  having a bilipped spathulate touch-sensitive stigma. The stigma becomes receptive two hours after anthesis i.e. between 2100-2145 h. At and before anthesis, the stigmatic lobes are tightly adpressed to each other, an indication of immature female sexual phase. Receptivity is characterized  by the unfolding of the two lobes by 180 whereby their inner  papillate surface gets exposed. The stigma remains receptive throughout the night till morning upto 0900-1000 h. Pollinated stigmas turn brown and the ovaries of such pistils swell grow rapidly and transform into fruits. At the base of the ovary, a very prominent nectary is present in the form of an annular disc. Before anthesis, nectar is not secreted at all.Nectar secretion initiates after anthesis and overlaps with stigma receptivity. By 2130-2230 h the corolla tube brims with nectar. Fruit formation starts in the last week of April and continues till September. Fruits are elongate, woody indehiscent capsules. Seeds are dispersed only after the fruits decompose and disintegrate. Seeds germinate within these fruits during June to mid- August.
Keywords : Kigelia pinnata, phenology, receptivity, anthesis, anther dehiscence, odour, nectar.

  Phenology of four species of Jatropha (Euphorbiaceae)

Divya Sharma
Department of Botany, School of Life Sciences, Dr. B.R. Ambedkar University, Agra-282002

e-mail:
divyasharma_agra@yahoo.co.in

  ABSTRACT

Worldwide Euphorbiaceae comprises of 300 genera and about 8000 spp. Jatropha a native of tropical America has more than 200 species widely distributed in tropics with a promise for use as an oil crop for biodiesel. Present communication deals with the phenological events in four species viz Jatropha integerrima, J. curcas, J. gossypifolia and J. podagrica growing in Agra. These are perennial, deciduous, erect shrubs or tree lets of about 2-6 feet in height. J. integerrima Leaf fall and Leaf renewal takes place simultaneously, but maximum leaf fall occurs during the month of December-February. Leaf renewal starts in the month of March and continues till October with maximum in the month of July and August. The flowers are bright red and star shaped. The plants produce flowers in racemose inflorescence with dischasial cyme pattern. The ratio of male to female flowers is 9:1. It flowers throughout the year with maximum flowering twice in the year during march-April and September-October. Fruit formation starts in the month of October to February. The fruit is a capsule. J. curcas In his species a pale brown and papery smooth pale brown bark is present on stem. The stem secretes copious, white coloured watery latex. It is slimy in nature but soon dries out and becomes brittle and brownish. Branches are glabrous, ascending and stout. Maximum leaf fall occurs during the month of February-April. Leaf renewal is highest during the months ofSeptember-October. The flowers are greenish-white in colour and are in racemose inflorescence, with dichasial cyme pattern, with male to female ratio as 8:1.Flowering takes place during the month of late July to late October. Maximum fruiting was recorded in October-December. Fruit is a capsule and the mature fruit dehisce passively and seeds fall offtogether with the capsule. J. gossypifolia The young leaves are deep purple and sticky, while the old leaves aregenerally glossy green, but some of them are purple in colour. Leaf fall occurs during the month of November-February and leaf renewal occurs in July-September. The flowers are red with yellow centres in middle and are produce in panicle cyme with male to female ratio as 8:1. Flowering starts from July and continues till August. The fruit is a capsule and fruiting continues from September till December.J. podagrica In J. podagrica stem is swollen and knobby with bristled scars. Leaves are orbicular-ovate, deeply 3-5 lobed with obtuse sinuses. Petiole is nearly 30cm across, red in colour. Leaf fall and leaf renewal occurs simultaneously. Leaf fall occurs in November-March with maximum leaf renewal in July-September. The flowers are bright red and salver shaped. The inflorescence is corymbose and the male to female ratio is 5:1. Flowering continues from March and lasts till October. The fruiting period starts from October-January and fruit is a capsule. The fruits are brownish black at maturity and dehisce by longitudinal splitting.

   

 
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