Botanica
https://doi.org/10.35513/Botlit.2022.1.9
2022, 28(1): 75–80
ISSN 2538-8657
Original research
Reproductive biology of green-stemmed and red-stemmed Basella
alba
Abolade Oluremi Bolaji 1*, Atanda Samuel Oladejo 2, Oluwatobi Isaac Adeniran
1
1
Obafemi Awolowo University, Department of Botany, Ile-Ife, Nigeria
Obafemi Awolowo University, Department of Crop Production and Protection, Ile-Ife, Nigeria
*Corresponding author. E-mail: abolaji@oauife.edu.ng
2
Abstract
Bolaji A.O., Oladejo A.S., Adeniran O.I., 2022: Reproductive biology of green-stemmed and red-stemmed
Basella alba. – Botanica, 28(1): 75–80. https://doi.org/10.35513/Botlit.2022.1.9
Basella alba is an important, underutilised vegetable rich in vitamins and consumed in many parts of the world.
However, the reproductive biology of this species is insufficiently known; therefore, this study was performed
aiming to fill this knowledge gap. Although green-stemmed and red-stemmed Basella alba share a lot of reproductive attributes in common, the obtained results showed differences in their flower bud apex colour, anther
colour, spike colour, days to 50% flowering, plant height at flower bud initiation and the mean number of flowers per spike. In both forms, the floral attributes favoured self-pollination. However, the possibility of crosspollination among them due to the activities of pollinators such as ants, moths, butterflies and bees suggests a
mixed mating system. Furthermore, both forms attained sexual maturity at varying periods, thus indicating the
existence of a temporal prezygotic barrier between them and limiting the chances of their hybridisation. They
could also be responsible for the ability to remain in their distinct forms even when they exist together in the
same habitat.
Keywords: germination percentage, isolating mechanism, pollen viability, self-pollination.
INTRODUCTION
The genus Basella (Basellaceae) comprises five
species: Basella excavata Eliot, Basella leandriana
H. Perrier, Basella madagascariensis Boivin ex
H.Perrier, Basella paniculata Volkens and Basella
alba L. (Eriksson, 2004). Basella excavata, Basella
leandriana and Basella madagascariensis are native
to Magadascar, Basella paniculata is native to South
and East Africa, while Basella alba has a pantropical distribution (Eriksson, 2004). Earlier recognised
Basella rubra is currently considered a red-stemmed
form of Basella alba (Cook, 2010; Deshmukh &
Gaikward, 2014).
Green-stemmed and red-stemmed forms of Basella alba are common vegetables among the Yoruba
tribe of Southwestern Nigeria and are referred to as
‘amunututu’. They are good sources of vitamins A
and C (Roy et al., 2010). They contain several phytoconstituents such as proteins, alkaloids, carbohydrates, polysaccharides, phenols, flavonoids, carotenoids, minerals and vitamins (Kumar et al., 2012).
They are helpful in phytomedicine in treating gonorrhoea, constipation, leprosy, dysentery, ulcer and
burns (Dixit & Goyal, 2011; Shantha et al., 2016).
Although there have been reports on some aspects
of the morphology and phytomedicinal potentials of
green-stemmed and red-stemmed Basella alba, there
75
Bolaji et al. || Reproductive biology of Basella alba
is a lack of information on their reproductive biology.
The specific objectives of this research were, therefore,
to investigate their reproductive attributes such as seed
germination percentage, days to seedling emergence,
floral structure, period of anthesis, pollen viability,
days to 50% flowering, plant height at flower bud initiation, pollinators, mode of fruit and seed dispersal
and reproductive isolating mechanisms.
MATERIALS AND METHODS
Seeds of green-stemmed and red-stemmed Basella alba accessions were collected from various locations within Southwestern Nigeria (Table 1). These
were authenticated at the IFE Herbarium located at
the Department of Botany, Obafemi Awolowo University, Nigeria. Seeds were sown in polythene bags
filled with sterilised topsoil and raised to maturity in
the screen house of the Department of Botany, Obafemi Awolowo University, Ile-Ife, Nigeria. The experiment was laid out in an utterly randomised design
while regular agronomic practices such as irrigation,
weeding and staking for optimal growth and devel-
opment were carried out regularly. A total number of
38 seedlings of green-stemmed Basella alba accessions and 45 seedlings of red-stemmed Basella alba
accessions were raised and studied. The study was
carried out from December 2018 to April 2020.
Data were collected from randomly selected
plants on the following parameters: the mean number
of days to seeding emergence, mean germination
percentage, the mean number of days to 50% flowering, floral attributes, mean plant height at flower
bud initiation, period to anthesis, percentage pollen
viability, types of pollinators, the mean number of
fruits per spike, mean number of seeds per spike, the
colour of ripe and unripe fruit, colour and types of
seeds and mode of seed dispersal.
The germination study was carried out on 8 cm
Petri dishes laid with 7 cm Whatman filter paper at
temperatures between 20°C and 30°C. Twenty seeds
drawn at random were placed on a wet filter paper inside a Petri dish, and this was done in three replicates.
The mean number of days to the radicle emergence
was documented, and the percentage of germinated
seeds was determined.
Table 1. Sources of green-stemmed and red-stemmed Basella alba plants used in the study. Numbers in brackets represent the
number of studied plants within the accession
Accession
BAIWO (10)
Form
Green-stemmed
Iwo
BAIFE (8)
Green-stemmed
Ile-Ife
BAONDO (5)
Green-stemmed
Ondo
BAEKITI (5)
Green-stemmed
Ekiti
BAOYO (5)
Green-stemmed
Oyo
BALAG (5)
Green-stemmed
Ijede
BRIWO (9)
Red-stemmed
Iwo
BRIFE (8)
Red-stemmed
Ile-Ife
BRONDO (10)
Red-stemmed
Ondo
BREKITI (7)
Red-stemmed
Ekiti
BROYO (5)
Red-stemmed
Ogbomoso
BRLAG (6)
Red-stemmed
Ijede
76
Source
Location
7.629444 °N
4.191111 °E
7.523056 °N
4.515833 °E
7.236111 °N
5.239722 °E
7.616389 °N
5.218333 °E
7.419167 °N
3.964722 °E
6.942778 °N
4.191111 °E
7.629444 °N
4.191111 °E
7.523056 °N
4.515833 °E
7.236111 °N
5.239722 °E
7.616389 °N
5.218333 °E
8.146111 °N
4.259167 °E
6.942728 °N
3.098056 °E
Comment
Cultivated in home gardens
Cultivated in school gardens
Cultivated in home gardens
Cultivated in gardens
Cultivated in church gardens
Cultivated beside home
Cultivated in home gardens
Cultivated in school gardens
Cultivated in home gardens
Cultivated in home gardens
Cultivated in school gardens
Cultivated in home gardens
Bolaji et al. || Reproductive biology of Basella alba
The pollen viability study was carried out by collecting pollen grains from freshly dehisced anthers
onto microscope slides. These were stained with
cotton-blue-in-lactophenol for 30 minutes. A total
of 100 pollen grains were examined using the light
microscope for percentage stainability following the
methods of Bolaji & Nwokeocha (2013). The wellformed and deeply stained pollens were considered
viable, while those with a collapsed outline, partially
stained or not stained, were considered non-viable.
The quantitative reproductive data obtained were
subjected to the General Linear Model (GLM) analysis
of variance (ANOVA). Results of data analysis were
presented as the mean and standard error (mean ± SE).
In addition, differences between means were evaluated
by applying Duncan Multiple Range Test (DMRT) at
p < 0.05. Statistical analyses were performed employing System Analysis Software (SAS, version 9.0).
Table 2. Comparison of reproductive characteristics between
green-stemmed and red-stemmed forms of Basella alba. Different letters in superscripts across a row indicate significant
differences between the means (p < 0.05)
Attributes
Green-stemmed Red-stemmed
(n = 38)
(n = 45)
Percentage of seed
germination (%)
72.40 ± 0.97a
75.50 ± 0.48a
Number of days to
seedling emergence
10.12 ± 3.15a
13.02 ± 4.11a
Plant height at flower
bud initiation (cm)
87.70 ± 9.05a
119.49 ± 6.80b
Days to 50% flowering
100.10 ± 3.60a
200.20 ± 4.07b
Mean number of flowers
per spike
22.16 ± 3.13
16.45 ± 1.83b
93.70a
94.50a
Mean fruit length (cm)
1.07 ± 0.03a
1.15 ± 0.02a
Mean fruit diameter
(cm)
2.20 ± 0.02a
2.25 ± 0.03a
RESULTS
Mean number of fruits
per spike
12.21 ± 4.59a
10.24 ± 3.20a
Analysis revealed that germination of greenstemmed Basella alba seeds was 72.40 ± 0.97%,
while that of red-stemmed Basella alba was 75.5 ±
0.48%, and no significant differences between them
were found (Table 2). The mean number of days
to seedling emergence was 10.12 ± 3.15 for greenstemmed and 13.02 ± 4.11 for red-stemmed plants.
The mean plant height at flower bud initiation was
87.70 ± 9.05 cm for green-stemmed Basella alba,
while 119.49 ± 6.80 cm for red-stemmed plants.
Significant differences were found between plant
height at flower bud initiation (p = 0.005). The mean
number of days to 50% flowering was 100.10 ± 3.60
for green-stemmed, whereas red-stemmed plants
spent significantly longer (p < 0.001) time to flowering, i.e. 200.20 ± 4.07 days (Table 2). The study
revealed that the mean number of flowers per spike
of green-stemmed plants was significantly higher
(p < 0.001) than of red-stemmed plants (22.16 ± 3.13
and 16.45 ± 1.83 flowers, respectively).
Anthesis of both forms of Basella alba occurred
between 8:00 a.m. and 12:00 noon. The pollens of
green-stemmed plants were powdery, light yellow.
The pollens of red-stemmed Basella alba differed
by deep yellow colour. No significant differences between the mean pollen viability were found (93.70%
and 94.50 %, respectively).
Mean seed length (cm)
0.65 ± 0.01a
0.64 ± 0.04a
Mean seed diameter
(cm)
1.25 ± 0.04a
1.20 ± 0.02a
Percentage pollen
viability (%)
a
The fruits of Basella alba are spherical juicy
drupes. The unripe fruits were green and deep purple when they ripened for both forms of this species.
The mean fruit length was 1.07 ± 0.03 cm and mean
diameter was 2.20 ± 0.02 cm for green-stemmed Basella alba, while the mean fruit length was 1.15 ±
0.02 cm and mean diameter was 2.25 ± 0.03 cm for
red-stemmed Basella alba. No significant differences
between the two forms of Basella alba by the mean
fruit length (p = 0.638) and fruit diameter (p = 0.223)
were revealed.
The mean number of fruits, and thus seeds, per
spike was 12.21 ± 4.59 for green-stemmed Basella
alba, while red-stemmed plants had 10.24 ± 3.20
(Table 2). According to the mean number of fruits
per spike, no significant differences were found between the two forms (p = 0.407).
The mean seed length was 0.65 ± 0.01 cm, while
the mean diameter was 1.25 ± 0.04 cm for greenstemmed Basella alba. The mean seed length of
red-stemmed plants was 0.64 ± 0.04 cm, and their
mean diameter was 1.20 ± 0.02 cm (Table 2). No significant differences were found between the green77
Bolaji et al. || Reproductive biology of Basella alba
stemmed and red-stemmed plants’ mean seed length
(p = 0.352) and seed diameter (p = 0.374). The two
forms flowered and fruited sequentially throughout
the remaining period of their life cycles.
DISCUSSION
Reproductive biology and systematics are interrelated (Anderson et al., 2002). Its importance in the
taxonomic description of species has been harnessed
by many researchers (Folorunsho & Olorode, 2008;
Ratha & Paramathma, 2009; Bolaji et al., 2020). This
study revealed that green-stemmed and red-stemmed
Basella alba plants were similar in their reproductive
characteristics. There were no significant differences
between the two Basella forms regarding seed germination percentage and the number of days to seedling
emergence, pollen viability, mean fruit length, mean
fruit diameter, the mean number of fruits per spike,
mean seed length and mean seed diameter (Table 2).
The lack of significant differences in these traits supports the opinion that the two Basella forms belong
to the same species. This point of view has been expressed by Roy et al. (2010).
Although the inflorescence, fruits and seeds were
similar in many respects, notable differences were
observed in their flower bud apex and anther colours.
While the flower bud was pink and the anther light
yellow in green-stemmed Basella alba, the flower
bud apex was deep purple, and the anthers were deep
yellow of red-stemmed Basella alba. This could be
why some researchers (Henry et al., 1987; Roy et al.,
2010) consider them as varieties. Understanding species’ reproductive biology helps clarify characters’
potential use and values in systematic treatments
(Anderson et al., 2002).
The percentage germination of the seeds was
notably high (72.40 ± 0.97 for green-stemmed and
75.50 ± 0.48 for red-stemmed Basella alba). According to Labhane et al. (2014), the traditional method of
studying the viability of seeds is by considering the
percentage of their germination. The number of days
to seedling emergence for both forms was similar
(10.12 ± 3.15 for green-stemmed and 13 ± 4.11 for
red-stemmed Basella alba). The high viability of the
seeds and the ability of the seedlings to emerge within a few days could have significantly contributed to
their reproductive success and ability to thrive easily
78
under varying environmental conditions. According
to Norman et al. (2021), seed germination and seedling emergence are the most critical and vulnerable
phases of a crop cycle. Therefore, they can predict
the extent of a speciesʼ success. Palada & Crossman
(1999) have also noted that Basella alba adapts easily to various soils and climates and is considered
one of the best tropical leaf-vegetable throughout the
tropical world.
It is noteworthy that from the number of days to
50% flowering and plant height at flower bud initiation, the red-stemmed Basella rubra spent a much
longer time (Table 2) in the vegetative phase than
the green-stemmed. This implies that the two Basella
alba forms attain sexual maturity at varying periods.
Conversely, even though the period of anthesis,
pollinators, fruit and seed dispersal agents were similar for both Basella alba forms, the timing of their
sexual maturity is such that green-stemmed Basella
alba would have flowered and started to produce
fruits long before red-stemmed Basella alba begins
to flower, thereby making hybridisation between the
two forms limited. This indicates the temporal prezygotic barrier, which could be responsible for their
ability to remain in their distinct forms even when
they occur in the same habitat. Prezygotic barriers
include spatial, temporal or behavioural differences
leading to sexual isolation, and they are the most
critical and effective barriers, given that they act
early in the life cycle of an organism to impose the
strongest impediment to gene flow, thereby preventing hybridisation (Widmer et al., 2009; Henrich &
Kalbe, 2016).
The bisexual nature of the flowers and the location of the anthers above and very close to the stigma, favour self-pollination in both forms. However,
the bright colouration of the perianths of the two species attracted pollinating insects such as ants, bees,
moths and butterflies, thereby encouraging crosspollination, suggesting that the breeding system in
both forms is a mixed mating system. According to
Holsinger (1996), the continuum between self-pollination and outcrossing in plants results in a mixed
mating system. Understanding the breeding system
of these two Basella alba forms could enhance their
effective genetic improvement through hybridisation
programmes by breeders, thereby enhancing their
utilisation by consumers. It is also key to their ef-
Bolaji et al. || Reproductive biology of Basella alba
fective conservation. According to Anderson et al.
(2001), the knowledge of the reproductive system of
plants is a central element in their effective conservation. Vivian-Smith et al. (2007) have also noted that
flowers of Anredera cordifolia (Basellaceae) attract
pollinators such as bees and ants.
Hybridisation between green-stemmed and redstemmed Basella alba could be enhanced by varying
their planting periods. Their flowering periods overlap so that outcrossing between them is enhanced.
This is worthwhile considering the temporary prezygotic isolation between them because of differences
in the time it takes for both species to attain the generative stage. Breeders could explore this information
in carrying out hybridisation programmes for the genetic improvement of Basella alba. The knowledge
of pollination, breeding systems and seed dispersal
of plant species could be used to enhance their conservation and restoration (Hamrick et al., 1991; Karron, 1991; Ramirez, 2006). We suppose that humans
mainly disperse seeds of both forms of Basella alba.
Vivian-Smith et al. (2007) have reported that Anredera cordifolia (Basellaceae) is also primarily spread
by humans and water.
ACKNOWLEDGEMENTS
The authors gratefully thank the laboratory staff
members of the Department of Botany, Obafemi
Awolowo University, Ile-Ife, Nigeria, for providing
some of the facilities used in this work.
REFERENCES
Anderson G.J., Bernardello G., Stuessy T.F., Crawford D.J., 2001: Breeding systems and pollination
of selected plants endemic to the Juan Fernandez
Islands. – American Journal of Botany, 88: 220–
233. https://doi.org/10.2307/2657013
Anderson G.J., Johnson S.D., Neal P.R., Bernardello G., 2002: Reproductive biology
and plant systematics: The growth of a symbiotic association. – Taxon, 51: 637–653.
https://doi.org/10.2307/1555019
Bolaji A.O., Nwokeocha C.C., 2013: Issues concerning reproductive isolation in rice hybrid swarm
involving Oryza sativa Linn., O. longistaminata A. Chev. et Roehr. and O. glaberrima Steud.
Located in Jebba, Nigeria. – International Journal
of Biological and Chemical Sciences, 7(5): 2040–
2049. https://doi.org/10.4314/ijbcs.v7i5.21
Bolaji
A.O.,
Idowu-Aiye
M.,
Moronfade H.O., 2020: Reproductive biology of four
weedy Euphorbia species from Ile-Ife, Nigeria. – Ife Journal Science, 22(1): 1–8.
https://doi.org/10.4314/ijs.v22i1.1
Cook A., 2010: Linnaeus and Chinese plants: A
test of the linguistic imperialism thesis. – Notes
and Records of the Royal Society, 64: 121–138.
https://doi.org/10.1098/rsnr.2009.0051
Deshmukh S.A., Gaikward D.K., 2014: A review of the
taxonomy, ethnobotany, phytochemistry and pharmacology of Basella alba (Basellaceae). – Journal
of Applied Pharmaceutical Science, 4(1): 153–165.
https://doi.org/10.7324/japs.2014.40125
Dixit U., Goyal V.C., 2011: Traditional knowledge
from and for elderly. – Indian Journal of Traditional Knowledge, 10: 429–438.
Eriksson R., 2004: Basellaceae. – In: Smith N. (ed.),
Flowering plants of Neotropics: 44–45. Princeton.
Folorunsho A.E., Olorode O., 2008: Biosystematic
studies in Annonaceae II. Vegetative and floral
morphological studies of some genera of Annonaceae in Nigeria. – Research Journal of Botany,
3(1): 1–8. https://doi.org/10.3923/rjb.2008.1.8
Hamrick J.L., Godt M.J.N., Murrawski D.A., Loveless M.D., 1991: Correlations between species
traits and allozyme diversity: Implications for
conservation biology. – In: Falk D.A., Holsinger K. (eds), Genetics and Conservation of Rare
Plants: 75–86. New York.
Henrich T., Kalbe M., 2016: The role of prezygotic isolation mechanisms in the divergence of two parasite species. – BMC Evolutionary Biology, 16: 245.
https://doi.org/10.1186/s12862-016-0799-5
Henry A.N., Kumari G.R., Chithra V., 1987: Flora of
Tamilnade, India, Ser. 1, 11. Coimbatore.
Holsinger K.E., 1996: Pollination biology and the
evolution of mating systems in flowering plants. –
Evolution Biology, 29: 107–149.
Karron J.D., 1991: Patterns of genetic variation
and breeding systems in rare plant species. – In:
Falk D.A., Holsinger K.E. (eds), Genetics and
Conservation of Rare Plants. New York.
Kumar V., Bhat Z.A., Kumar D., Khan N.A., Cha79
Bolaji et al. || Reproductive biology of Basella alba
shoo I.A., Ara I., 2012: Gastroprotective effect
of leaf extracts of Basella alba var. rubra against
experimental gastric ulcers in rats. – Brazillian Journal of Pharmacognosy, 22: 657–662.
https://doi.org/10.1590/s0102-695x2012005000032
Labhane N.M., Dongarwar N.M., Borkar S.J., 2014: In
vivo study of morphology of embryo in the medicinal plant, Basella alba Linn. (Basellaceae). – International Journal Life Sciences, 2(4): 329–333.
Norman P.E., Danquah A., Asfaw A., Tongoona P.B., Danquah E.Y., Asiedu R., 2021:
Seed viability, seedling growth and yield in
White Guinea Yam. – Agronomy, 11(2): 1–10.
https://doi.org//10.3390/agronomy11010002
Palada M.C., Crossman M.A., 1999: Evaluation of
tropical leaf vegetables in the Virgin Islands. –
In: Perspectives on New Crops and New Uses:
388–393. Alexandria.
Ramirez N., 2006: Reproductive biology and plant species selection for habitat restoration in the Vezuelan
Gran Sabana Plateau. – INCI, 31(5): 114–124.
AOB
ASO
OIA
80
http://orcid.org/0000-0002-7403-4460
http://orcid.org/0000-0002-3102-2339
http://orcid.org/0000-0002-8433-1418
Ratha P.K., Paramatha M., 2009: Potentials and Jatropha species wealth in India. – Current Science,
97: 1000–1004.
Roy S.K., Gangopadhyay G., Mukherjee K.K.,
2010: Is stem twinning form of Basella alba L.
a naturally occurring variant? – Current Science,
98(10): 1370–1375.
Shantha T.R., Patchaimal P., Prathapa M., Kumar R.,
Tewari D., Bharti V., Venkateshwarlu G., Mangal A.K., Padhi M.M., Dhiman K.S., 2016: Pharmacognostical standardization of upodika, Basella alba Linn, an important ayurvedic antidiabetic
plant. – Ancient Science of Life, 36(1): 35–41.
https://doi.org/10.4103/0257-7941.195411
Vivian-Smith G., Lawanson B.E., Turnbull I.,
Downey P.O., 2007: The biology of Australian
weeds. 46. Anredera cordifolia (Ten). Steenis. –
Plant Protection Quarterly, 22(11): 2–10.
Widmer A., Lexer C., Cozzolino S., 2009: Evolution
of reproductive isolation in plants. – Heredity,
102: 31–38. https://doi.org/10.1038/hdy.2008.69