Variations in size, leaf morphology, and fruit characters among 25 populations of Luffa aegyptiaca

Abstract

Variations in 25 populations of Luffa aegyptiaca L. in southwestern Nigeria and their possible causes were studied. The variations were most pronounced in the leaf, especially in texture, invagination, area, and dry weight. Shoot and fruit dry weights also showed considerable variation. While mean seed dry weight showed remarkable constancy in the populations studied, mean seed number per fruit varied greatly.Populations growing in acid soil with low nutrient content had deep leaf invaginations, small leaf areas per shoot, and small leaf, shoot, and fruit dry weights, while populations growing in neutral or basic soils with high nutrient content had shallow leaf invaginations, large leaf area per shoot, and large leaf, shoot, and fruit dry weights.When seeds from a population with deep leaf invagination and small leaf area were grown in soil from the site of a population with shallow leaf invagination and large leaf area, the resulting plants developed the characteristics of the second population. The reciprocal procedure gave a similar result. The variations in soil were thought to be responsible for the variation noted in leaf morphology, size, and weight and for variation in shoot and fruit dry weights. Light was partially responsible for the variations in the leaf colour and in the prominence of leaf veins.

Experimental studies on some observed variations in Luffa aegyptiaca

“…The leaves of seedlings which received phosphate were glossy, the leaves of those which received nitrate were smooth, and the leaves of those without either were coarse. This result is in agreement with observations in an earlier paper (Okusanya et al 1981) in which the populations with smooth or glossy leaves were those from phosphate-or nitrate-rich soils (populations 8, 9, 16, 17, 20, and 23).…”

“…The effects of soil type on seedling growth support field observations (Okusanya et al 1981) in which populations of L. aegyptiaca with large leaf areas and high leaf, shoot, and fruit dry weights are generally those in soils with high humus and nutrient content; while those with small leaf areas and low leaf, shoot, and fruit dry weights are those in soils with low humus and nutrient contents (Okusanya et al 198 1, Tables 1 and 2). For example, within the type B group of L. aegyptiaca populations which have the same characteristics as described in Okusanya et al (1981), the Sagamu population, which has larger leaf area and higher leaf and shoot dry weights than the Onigbedu population, grows in soil with higher humus and nutrient contents than those on which the Onigbedu population grows.…”

“…Since there is a high correlation between leaf area and fruit dry weight ( r = 0.69) (Okusanya et al 1981), and since the seedlings which received calcium, nitrate, and potassium or calcium and nitrate had the highest leaf area values, those seedlings are likely to produce large fruits. Consequently, variations in the nutrient status of the soil most probably in nitrate and calcium can also be linked with the variations in fruit size.…”

“…In an earlier paper (Okusanya et al 1981), plants with the greatest difference in size and appearance were those from populations growing in red lateritic earth with low concentrations of mineral nutrients mainly calcium, potassium, magnesium, nitrogen (nitrate), and phosphorus (phosphate). To determine which of these mineral elements might be responsible for the variations, seedlings in red lateritic earth in 7.5-cm pots were treated with solutions of the following: (i) amrnonium nitrate (N only), (ii) potassium nitrate (N and K), (iii) calcium nitrate (Ca and N), (iv) calcium nitrate and potassium sulphate (Ca, N, and K), (v) calcium chloride (Ca only), (vi) potassium sulphate (K only), (vii) magnesium sulphate (Mg only), (viii) orthophosphoric acid (P only), and ( i x ) distilled water.…”

Evaluation of Sponge Gourd (Luffa cylindrical L.) Inbred Lines for Growth Potential and Fruit Quality in Thua Thien Hue Province, Central Vietnam

“…The smallest fruit was obtained in 15-MN2. Sponge gourd is an annual vine with tendrils and large [16], so it needs a supporting frame as trellis system to grow and spread. Harvesting was more easily carried out when fruit peduncle recorded as long as well.…”