Nigerian Journal of Agriculture, Food and Environment. 14(1): Published March, 2018 Willie, E. S. et al., 2018

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1 PRELIMINARY EVALUATION OF MORPHOLOGICAL, NUTRITIONAL AND PHYTOCHEMICAL DIFFERENCES BETWEEN MALE AND FEMALE INDIVIDUALS OF FLUTED PUMPKIN (Telfairia occidentalis Hook. F.) Willie, E. S., Nmeregini, U., and Akpan, A. U. Department of Agronomy, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria. Corresponding Author ABSTRACT An experiment involving field planting and laboratory analysis was conducted to study the morphological, nutritional, and phytochemical differences between male and female plants of fluted pumpkin (Telfairia occidentalis Hook. F.) in The field planting was done at the National Root Crops Research Institute Farm, Umudike, South-eastern Nigeria. It was laid out as a randomized complete block replicated three times. Data were taken on some morphological parameters of parts of the shoots. Parts of shoots and roots of male and female plants were analyzed for nutritional and phytochemical composition. Results indicated that female plants had significantly higher (p<0.05) stem diameter, petiole length, petiole diameter, tendril diameter, harvestable vegetable weight, edible vegetable weight, and 10 leaf weight, than male plants. Roots of female plants had significantly higher (p<0.05) moisture content than those of male plants. There was no significant difference between the roots of male and female plants in fat, crude protein, crude fibre, ash and carbohydrate composition. Stems of female plants had significantly higher (p<0.05) moisture content than those of male plants. There was no significant difference between male and female stems in fat, crude protein, crude fibre, ash and carbohydrate composition. Moisture content in the leaves of female plants was significantly higher (p<0.05) than in male plants. There was no significant difference between male and female plants with respect to the fat, crude protein, ash and carbohydrate composition of their leaves. Male plants had higher (p<0.05) phytate and trypsin inhibitor contents than female plants. There was no significant difference between male and female plants in tannin, saponin and oxalate composition. Female plants had stems with significantly higher tannin content than male plants (p<0.05) while male plants had significantly higher (p<0.05) saponin and phytate contents in stems, than females. There was no significant difference between male and female plants in oxalate and trypsin inhibitor contents. Male plants had significantly higher (p<0.05) saponin content than females. There was no significant difference between males and females in tannin, oxalate and trypsin inhibitor in the leaves. Female plants had more (p<0.05) iron in their roots, stems and leaves than male plants. Possibly, the contrasting morphological, nutritional and phytochemical features of the male and female plants at flowering might be useful in differentiating between the sexes in the plant during the vegetative phase of the it s life. It was deduced that if a consumer s interest is in the fibre content of fluted pumpkin vegetable, he should go for male shoots, and if it is in the iron content, he should go for female shoots. Keywords: Fluted pumpkin, dioecious, male plants, female plants. INTRODUCTION Fluted pumpkin (Telfairia occidentalis Hook. F.), a herbaceous climber usually cultivated as an annual, belongs to the Cucurbitaceae family of dicotyledonous plants and originated from tropical West Africa (Schippers, 2000). Although a perennial by nature, it is usually grown as an annual (Ogbonna, 2009). It is prized for its leaves and seeds, which constitute an important component of the diet in many Nigerian homes (Ayanwale and Abiola, 2007; Odiaka et al, 2008). Fluted pumpkin is a dioecious species, and the sex of any given individual plant cannot be ascertained until flower appearance, which takes about 13 weeks for the male, and 16 for the female. The inability to determine the sex of an individual plant before flowering is a challenge to farmers who would handle the two sexes differently, to maximize profits, if they could distinguish between them earlier than at reproductive maturity. Fluted pumpkin roots have high alkaloid content and their extracts, which have high mammalian toxicity, are used in controlling rodents, as well as killing fish (Ajibesin et al, 2002). The plant also contains considerable amounts of anti-nutrients such as phytic acid, tannin and saponin (Ladeji et al, 1995). The appearance of flowers in the male plants marks the commencement of senescence and drop in leaf yield in those plants. An investigation into the differences between flowering male and female individuals of fluted pumpkin with respect to morphological, nutritional and phytochemical characteristics might help to distinguish the male plants from the females during the vegetative stage of development of the crop plant, and also provide useful information to producers and consumers of the vegetable. The objectives of the study were to: i) study the morphological NJAFE VOL. 14 No. 1,

2 differences between male and female plants in T. occidentalis and ii) investigate differences in the nutritional and phytochemical contents of the roots, stems and leaves of male and female plants in the crop species. MATERIALS AND METHODS The Experimental Site The field experiment was conducted in 2016 at the National Root Crops Research Institute, Umudike. Research Farm. The co-ordinates of the field plot lies between Latitude ¹ ¹N and Longitude ¹ ¹E on an elevation of 100 metres above sea level. Umudike is located within the tropical rainforest zone of Nigeria with a mean annual rainfall range of mm, which is spread over nine to ten months in bimodal rainfall pattern. The monthly minimum air temperature ranges from 20 0 C to 24 0 C while the monthly maximum air temperature ranges from 28 0 C to 35 0 C, and the relative humidity varies from 51% to 87%. Average number of sunshine hours varies between 3 and 7, and appears always lowest in July and August (NRCRI, Umudike Meteorological Station, 2016). Field Layout The fluted pumpkin crop was planted in the field on 15 th August, The experiment covered a total area of 270m 2. After the land had been ploughed and harrowed with a tractor, planting was done in 21 beds, each measuring 3m x 2m. The distance between beds was 1m. In each of the 21 beds, six (6) seeds were planted at a spacing of 1m inter-row and 1m intra-row, giving a total population of 126 (one hundred and twenty-six plants), equivalent to 100, 000 plants per hectare. Beds that had both male and female individuals were randomly sampled for a study of morphological, nutritional and phytochemical differences between the sexes. The fluted pumpkin seeds used were sourced from a local market at Ndoro in Ikwuano Local Government Area of Abia State, South-eastern Nigeria. The field was weeded manually anytime the need to do so arose, throughout the duration of the work. Data Collection Data were collected on morphological, nutritional and phytochemical characters at flowering. These were stem diameter, which is the thickness of the main vine in a given plant, petiole length and diameter, tendril diameter, harvestable vegetable weight, edible vegetable weight, and weight of 10 leaves. Stem diameter (mm) was obtained as the thickness of the main vine using a pair of vernier sliding calipers. Petiole length (mm) was obtained as the length of the leaf stalk, using a ruler. Petiole diameter (mm) and tendril diameter were obtained using a pair of vernier sliding calipers. Harvestable vegetable weight (g) was obtained as the weight of the vegetable harvest of each sampled plant (male and female), including the leaves and shoot, using a weighing scale. Edible vegetable weight (g) was obtained as the weight of edible portion of the harvestable vegetable weight of male and female plants, using a weighing scale. Ten (10) leaf weight (g) was obtained as the weight of 10 leaves of each of the sampled male and female plants, using a sensitive weighing balance (model: Scout Pro SPU 601, manufactured by Ohaus Corporation, Pine Brook, New Jersey, United States of America). Nutritional and phytochemical assays were determined at flowering. Beds that showed both male and female plants were randomly sampled by uprooting the whole plant, taking out as much root as possible. Each plant was separated into three parts (roots, stem and leaves). Nutritional analysis of the nutrient, anti-nutrient and mineral (iron) composition was done for each plant part of each sex. Moisture content was determined by the gravimetric method as described by Bradley Jnr (2003). Fat content was determined by the continuous solvent extraction method using a soxhlet apparatus, as described by Min and Bott (2003). Protein content was determined by the Kjeldahl digestion method described by Chang (2003). Crude fibre content was determined by the method described by Bemiller (2003). Ash content (%) was determined using the incineration method (AOAC, 2000). Carbohydrate content was calculated using a formula described by James (1995), thus: % Carbohydrate = % (protein + fat + fibre + ash + moisture content). Tannin content (%) was determined using the Folin-Denis spectrophotometric method as described by Kirk and Sawyer (1991). Oxalate composition (%) was determined following the method described by Onwuka (2005). Saponin content (%) was determined using the method described by AOAC (2000). Phytate content (%) was determined using the Bi-pyridine colorimetric method (Onwuka, 2005). Trypsin inhibitor content was determined using the colorimeter method described by Onwuka (2005). Fe content (mg) was determined by Atomic absorption spectrophotometer following the dry ash acid extraction method (Carpenter and Hendricks 2003). Statistical Analysis of Data For any given parameter, sample means of the two sexes - males and females - were obtained and compared with each other by use of independent student s t- test. NJAFE VOL. 14 No. 1,

3 RESULTS AND DISCUSSION Table 1 presents the mean values and t-test comparison in respect of the seven morphological characters studied. Female plants had significantly higher stem diameter (p<0.01), petiole length (p<0.05), petiole diameter (p<0.05), tendril diameter (p<0.01), harvestable vegetable weight (p<0.05), edible vegetable weight (p<0.01), and 10 leaf weight (p<0.01) than male plants. The mean values and t-test comparison in respect of nutritional composition of the roots, stems and leaves of the male and female individuals of the fluted pumpkin studied are shown in Table 1. The roots of female plants had significantly higher moisture content (p<0.05) than the roots of male plants, and there was no significant difference between the roots of male plants and those of female plants in fat, crude protein, crude fibre, ash and carbohydrate composition. The stems of female plants had significantly higher moisture content (p<0.05) than those of male plants, whereas there was no significant difference between the stems of male plants and those of female plants in fat, crude protein, crude fibre, ash and carbohydrate contents. The leaves of female plants had significantly higher moisture content (p<0.05) than the leaves of male plants, and there was no significant difference between the leaves of male plants and those of female plants with respect to their fat, crude protein, ash and carbohydrate contents. The roots, stems, and leaves of female plants had significantly higher iron contents (p<0.01), than those of male plants. Table 1. Means and t-test comparison for some morphological and nutritional parameters in male and female plants of fluted pumpkin Parameter Male Female t-test comparison Stem diameter (mm) ** Petiole length (mm) * Petiole diameter (mm) ** Tendril diameter (mm) ** Harvestable vegetable weight (g) * Edible vegetable weight (g) * 10 leaf weight (g) ** Moisture content of root (%) * Fat content of root (%) ns Crude protein content of root (%) ns Crude fibre content of root (%) ns Ash content of root (%) ns Carbohydrate content of root (%) ns Moisture content of stems (%) * Fat content of stems (%) ns Crude protein content of stems (%) ns Crude fibre content of stems (%) ns Ash content of stems (%) ns Carbohydrate content of stems (%) ns Moisture content of leaves (%) * Fat content of leaves (%) ns Crude protein content of leaves (%) ns Crude fibre content of leaves (%) * Ash content of leaves (%) ns Carbohydrate content of leaves (%) ns Iron content of roots (%) ** Iron content of stems (%) ** Iron content of leaves (%) ** N/B: ns non-significant; * - significant at p<0.05; ** - significant at p<0.01 Table 2 presents the mean values and t-test comparison in respect of the antinutrient content of the roots, stems and leaves of the male and female plants of fluted pumpkin studied. The roots of male plants had significantly higher phytate and trypsin inhibitor contents (p<0.01) than the roots of female plants, and there was no significant difference between the roots of male plants and those of female plants in tannin, saponin, and oxalate contents. The NJAFE VOL. 14 No. 1,

4 stems of female plants had significantly higher tannin content (p<0.05) than those of male plants. The stems of male plants had significantly higher saponin (p<0.05) and phytate (p<0.01) contents than those of female plants, while there was no significant difference between the stems of male plants and those of female plants in oxalate and trypsin inhibitor contents. The leaves of male plants had significantly higher saponin (p<0.05) and phytate (p<0.01) contents than the leaves of female plants. There was no significant difference between the leaves of male plants and those of female plants in their tannin, oxalate, and trypsin inhibitor contents. Table 2. Means and t-test comparison for some anti-nutritional contents in roots, stems and leaves of male and female individuals of fluted pumpkin Anti-nutritional content Male Female t-test comparison Tannin content of roots (%) ns Saponin content of roots (%) ns Phytate content of roots (%) ** Oxalate content of roots (%) ns Trypsin inhibitor content of roots (Tui/g) ** Tannin content of stems (%) * Saponin content of stems (%) * Phytate content of stems (%) * Oxalate content of stems (%) ns Trypsin inhibitor content of stems (Tui/g) ns Tannin content of leaves (%) ns Saponin content of leaves (%) * Phytate content of leaves (%) ** Oxalate content of leaves (%) ns Trypsin inhibitor content of leaves (Tui/g) ns N/B: ns - not significant; * - significant at p<0.05; ** - significant at p<0.01. The observation that female plants had significantly higher stem diameter, petiole length and diameter, tendril diameter, harvestable vegetable weight, edible vegetable weight, 10 leaf weight, and moisture content of roots than males, is in agreement with the finding of (Asiegbu, 1985) who reported that female plants are more vigorous than male plants and produce higher vegetative yields. It is also in line with the observations of local farmers, who are traditionally more protective of young plants (in the vegetative phase of development) that appear to be more vigorous than others, in the belief that the more vigorous plants have a higher probability of turning out to be females than those that are less vigorous. These local farmers are usually (but not always) right as some plants that show vigour during the vegetative phase end up expressing maleness. Also, in the market place, vegetables with a vigorous appearance are more attractive to consumers than those that look lean and scrawny. Larger morphological features, especially in respect of leaves and green stems, are associated with greater photosynthetic ability, which the female plants need in order to sustain their physiologically more demanding reproductive functions, including fruiting. Also, thicker stems and tendrils offer additional strength to stems of female plants which need to be strong in order to carry the weight of pods that often hang down on a climbing vine. The results of this study seem to validate the belief of local fluted pumpkin farmers. The observation that stems and leaves of female plants had significantly higher moisture contents than those of the males may also be related to the reproductive roles of the sexes. Female plants need to have higher moisture content in order to be able to cope with the physiological demands of fruiting, unlike the males, whose sexual function seems to end in the production of pollen. The observation that stems and leaves of male and female plants did not differ as to fat, crude protein, ash, and carbohydrate contents, and that males had significantly more crude fibre than females, while females had higher iron content than males, is of interest, especially as the vegetable is known to be used in the treatment of malnutrition and anaemia in man. From these observations, it could be deduced that if a consumer s interest is in the fibre content of the fluted pumpkin vegetable, he should go for male shoots, and if it is in the iron content, he should go for female shoots. CONCLUSION The male and female plants of fluted pumpkin studied exhibited differences as well as similarities in morphological, nutritional, and phytochemical parameters. The results corroborated findings from past studies and tended to validate the belief of local fluted pumpkin farmers. It is possible that the contrasting morphological, nutritional and phytochemical features of the male and female plants at flowering might be useful in differentiating between the sexes in the crop plant during the vegetative phase of the plant s life. It could be deduced that if a consumer s NJAFE VOL. 14 No. 1,

5 interest is in the fibre content of fluted pumpkin vegetable, he should go for male shoots, and if it is in the iron content, he should go for female shoots. REFERENCES Ajibesin K. K., Bala, D. N., Ekpo, B. A. J., and Adesanya, S. A Toxicity of some plants implicated as poisons in Nigeria. Nigerian Journal Medicinal plant Production 6:7-9. AOAC International Official methods. 17th edition. Association of Analytical Chemists. Asiegbu, J. E Characterization of sexes in fluted pumpkin, growth and yield in the male and female sexes. Gartenbawissentschatt Scientia Horticulture 50 (60) Ayanwale, A. B. and Abiola, M. O Efficiency of fluted pumpkin production under tropical conditions. International Journal of Vegetable Science, Vol. 13 (3): Bemiller, J. N Crude Fibre Analysis. In: Food Analysis 3rd Edition Kluwer Academic/ Plenum Publishers, New York; pp Bradley Jnr. R. L Moisture and total solids analysis. In: Food Analysis 3rd Edition Kluwer Academic/ Plenum Publishers New York pp Carpenter C. E and Hendricks, D. G Mineral Analysis In: Food Analysis 3rd Edition Kluwer Academic/ Plenum Publishers New York pp Chang S. M. K Protein Analysis. In: Food Analysis 3rd Edition; Kluwer Academic/Plenum Publishers, New York; pp James, C. S Experimental methods in analytical chemistry of foods. Chapman and Hall, New York. Pp. 28. Kirk R. S and Sawyer, R Pearson composition and Analysis of Food; 9th Edition. Hayman Publishers. Ladeji, O., Okoye, Z. S. C. and Ojobe, T Chemical evaluation of the nutritive value of leaf of fluted pumpkin (Telfairia occidentalis). Food Chemistry 53: Min, D. B. and Bott. J. M Crude Fat Analysis. In: Food Analysis 3rd Edition Kluwer Academic/ Plenum Publishers, New York; pp NRCRI Agrometeorological unit Report, National Root Crops Research Institute, Umudike, Odiaka N. I., Akoroda M. O, and Odiaka E. C Diversity and production methods of fluted pumpkin (Telfairia occidentalis Hook F.). African Journal of Biotechnology 7(8): Ogbonna, P. A Pod portion and type effects on sex, growth and yield in fluted pumpkin. African Crop Science Journal 16 (3): Onwuka G. I Food Analysis and instrumentation, theory and practice; 1st Edition, Naplithelin Prints, Lagos. Schippers, P. R African indigenous vegetables: An overview of the cultivated species. Chantam, UK: NRI/CTA, pp: 214. NJAFE VOL. 14 No. 1,