Experimental
Family Elaeagnaceae is represented by three genera, two of which, Elaeagnus and Hippophae, are found in India. Plants belonging to this group are hardy and actinorhizal, hence thrive well in extremely adverse climate and nutrient-deficient soils. Elaeagnus angustifolia L. (Syn: Elaeagnus hortensis Bieb.) is a small Eurasian tree with dark brown branches bearing silvery young shoots. Fruits are dry and ellipsoid to oblong in shape with thick stony endocarp. The species is distributed from Spain in west to China in the east through western and central Asia (Hooker, Reference Hooker1890). In India, the species is found in Ladakh, the Western Trans-Himalayan region of the country.
Ladakh is one of the loftiest and coldest inhabited places in the world. The region is characterized by wide seasonal as well as by diurnal variation in temperature. Annual precipitation is < 250 mm which is received mostly in the form of snow during winters (Humbert-Droz and Dawa, Reference Humbert-Droz and Dawa2004). The growing season varies from 6 to 8 months, depending on altitude. The region comprises two administrative districts, namely Leh and Kargil. Russian olive (E. angustifolia) is grown in both the districts on cultivated lands as multipurpose tree. For the characteristic brown red colour and excellent finish of its wood, the species is used for making pillars of traditional houses and furniture. Leaves and twigs are lopped and fed to domestic animals during winters when there is dearth of fodder. Fruits are edible. However, in Leh, its fruits do not mature due to shorter growing season. Being actinorhizal in nature, the plant also fixes atmospheric nitrogen.
Variation at infra-specific level in Russian olive has been reported from different regions within its distribution range (Musegjan, Reference Musegjan1958; Goncharova and Glushenkova, Reference Goncharova and Glushenkova1990; Lancaster, Reference Lancaster1993; Huang and Jiang, Reference Huang and Jiang2005). However, no such infra-specific taxa have been reported from India so far. Presence of this species in Ladakh has been reported by various taxonomists working on the flora of this region (Hooker, Reference Hooker1890; Stewart, Reference Stewart1917; Kachroo et al., Reference Kachroo, Sapru and Dhar1977; Chaurasia and Singh, Reference Chaurasia and Singh1996; Singh et al., Reference Singh, Dwivedi and Ahmed2008), but none has reported any variant of this species from this region. Nonetheless, ethnic community in this region has been growing five different variants of this species since a long time. The community calls this species as sersing and the variants as bee, chapacha, balti, marpo and ringmo. The variants are distinguished from each other by fruit size and colour.
This preliminary study is aimed at characterizing the variants of Russian olive growing in Ladakh. We also tried to find out the morphometric differences among these variants and to test whether these differences are significant or not.
For this study, 50 fruits of each type were sampled from the Poyne village of Kargil district. In order to minimize environmental variations, fruits were collected from the trees of almost same size (of 3–4 m height) and vigour. In addition to that, the fruits were collected from middle of the canopy and from the south facing side only. The fruits were collected during second week of November, at the end of growing season in 2009. Fruits were packed in polythene bags and were brought to the laboratory of Sher-e-Kashmir University of Agricultural Sciences and Technology, Leh, for further studies. Length and diameter of fruits and seeds were taken up to two decimal place of a centimeter using Digimatic Calipers. Fruit and seed weights were taken with the help of an electronic balance. The data were statistically analysed using statistical software SPSS 16.0 (SPSS, Inc., Cary, NC, USA).
Discussion
Statistically significant differences among the five variants were observed for all the fruit and seed characters studied (Tables 1 and 2). Average fruit length and diameter ranged 1.43–2.33 cm and 1.08–1.45 cm, respectively. Average fruit weight varied from 0.49 to 0.92 g (Table 1). The fruits of ringmo sersing were the longest and that of bee were the smallest. In fact, the variant bee had the lowest values for all the fruit characters studied. Thus, the morphometric data for this variant conforms to its local name which literally means ‘small fruited’ variety. The fruits of chapacha variant resembled much with that of bee. Whatever small differences between the two existed, those were statistically significant. Another striking difference between the two was the absence of fruit stalk (sessile fruit) in chapacha. The longest fruit was that of ringmo sersing, literally meaning ‘long fruited’ variety.
Table 1 Fruit characters of five different variants of Russian olive grown in Ladakh
Grouping is based on Student Newman–Keuls test.
a,b,c,d,e The superscript letters represents different groups which are statistically different from each other.
**, Significant at 1% level of significance.
Table 2 Seed characters of five different variants of Russian olive grown in Ladakh
Grouping is based on Student Newman–Keuls test.
a,b,c,d,e The superscript letters represents different groups which are statistically different from each other.
**, Significant at 1% level of significance.
Similarly the fruits of marpo and balti variants were alike except for the pattern of colour development. In the balti variant, red colour was developed only on the portion of fruit which was exposed to direct sunlight (Supplementary Fig. S1, available online only at http://journals.cambridge.org), rest was silvery brown in colour. On the other hand red colour of fruits in marpo sersing was uniformly developed, regardless of exposure. The meaning of ‘marpo’ in Ladakhi language is red.
Goncharova and Glushenkova (Reference Goncharova and Glushenkova1990) found three different fruit morphological forms of Russian olive viz. small brown-red, small silver-green and large brown in Uzbekistan. Baranov and Kositzyn (Reference Baranov and Kositzyn2003) reported a variety with smaller fruit size (average weight, 0.239 g; average length, 0.97 cm and average width, 0.64 cm) from Russia. A variety of Russian olive (E. angustifolia var. iliensis) with fruits larger than those of commonly grown variety in Kazakhstan has been reported by Musegjan (Reference Musegjan1958). A variant of the species in the UK is reported by Lancaster (Reference Lancaster1993) as ‘Quicksilver’.
These reports are indicators of differentiation of this species in to different infra-specific taxon through out its distribution range. Morphometric data from this study suggest presence of morphologically distinct forms of Russian olive even in Ladakh. However, only morphological data are not sufficient to designate these forms as separate taxonomic units at infra-specific level. Further studies at biochemical and/or genetic level are necessary for that.
Acknowledgements
The authors are thankful to Dr SS Sharma, Associate Professor, Department of Basic Sciences, College of Forestry, University of Horticulture and Forestry, Solan, for going through the manuscript and for his valuable suggestions. They are also grateful to Dr GA Parrey, Associate Director, Regional Agricultural Research Station, SKUAST (K), Leh, for the logistics provided by him to carry out this study.
