Introduction:The purpose of this study was to establish reference ranges of total thyroid volume among clinically euthyroid Nepalese population using Ultrasonography and correlate this volume with age, sex, individual's built and geographic location. Methods:This was a prospective cross sectional study involving 485 clinically euthyroid individuals. B -mode Ultrasonography was used to measure the total thyroid volume by combining the volume of both the lobes obtained by using formula for prolate ellipsoid. Age specific reference values for thyroid volume were obtained and Pearson correlation test was used to see the relationship with various factors.Results: Among 485 individuals between 1 to 83 years of age, 221(45.57%) were males and 264(54.43%) were females. Maximum [354 individuals (72.99%)] were from hilly region and minimum [16 individual (3.30%)] were from Himalayan region. Mean thyroid volume was 6.629 ± 2.5025 ml. In general, thyroid volume was found to be more in older individuals than in young age group. There was no significant difference of thyroid volume between males and females. Thyroid volume best correlated with body surface area (r=0.444, p<0.0001). The volume had a positive correlation with weight (r=0.443, p<0.0001), body mass index (r=0.371, p<0.0001) and height (r=0.320, p<0.0001) of the individual. Conclusions:This study estimated the reference range of total thyroid volume for Nepalese population. These ranges are significantly lower than the WHO/ICCIDD thyroid volume references and reference values obtained in various other countries. Total thyroid volume best correlated with Body surface area.

Cymbidium aloifolium is known for its ornamental and medicinal values. It has been listed as threatened orchid species. In this study, in vitro propagated C. aloifolium plantlets were interacted with the Piriformospora indica. The growth assay was performed for 45 days; the plant growth pattern such as number and length of roots and shoots were measured. Microscopic study of the root section stained by trypan blue was done to detect the peloton formation. The methanol extracts of the fungal colonized plant as well as uncolonized (control) plant were prepared and various metabolites were identified by gas chromatography mass spectroscopy. Acclimatization was done in a substrate composition of coco peat: gravel: charcoal in ratio 2:2:1. P. indica-colonized plantlet showed the highest growth with the formation of clamdospore in the root section. The growth regulator such as auxin, ascorbic acid, andrographolide, hexadecanoic acid, and DL-proline were identified. After three months of field transfer, plantlet colonized by P. indica survived and remained healthy as compared to uncolonized control plantlet.

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Abstract:In vitro seed germination and seedling development of Phaius tancarvilleae (L'Her.) Blume. was carried out on 0.8%(w/v) agar solidified MS Medium (Murashige and Skoog, 1962) without hormones or supplemented with different concentration and combination of Naphthalene acetic acid (NAA) and 6-benzylaminopurine (BAP). MS medium supplemented with 0.5 mg/l of BAP was the most ideal condition for early seed germination, protocorm formation and development of seedlings. Germination started after 7 weeks of culture and complete seedlings were obtained after 24 weeks of culture. This protocol might be helpful for mass propagation of orchids by asymbiotic seed germination.

A comparative study on in vitro seed germination and seedling development of Cymbidium aloifolium (L.) Sw., an epiphytic medicinal orchid, was carried out on four different conditions of Murashige and Skoog (MS) and Knudson (KC) medium viz. full, ½. ¼ strength and medium supplemented with 0.5mg/l BAP (benzyl amino purine) and 0.5mg/l NAA (Naphthalene acetic acid). Varied response in terms of seed germination, protocorm formation and seedling development was observed on two different media. Medium supplemented with hormones favored optimum condition for the germination (approx. 90%) of seeds followed by full, ½ and ¼ strength on both MS & KC media. MS medium supplemented with 0.5mg/l BAP and 0.5mg/l NAA showed comparatively better response within 7 weeks of culture than other conditions of MS medium as well as KC medium. Based upon the results, it was found that MS medium was more effective than KC medium for germination, protocorm and plantlet formation. The present study has provided useful information that the high concentration of nutrient compounds supplemented with hormones are required for earlier in-vitro germination and plantlet development from immature seeds of C. aloifolium. It could be an important protocol to conserve this important orchid species by establishing an efficient in vitro regeneration system using immature seed culture. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 51-56 DOI: http://dx.doi.org/10.3126/njst.v14i1.8878

Orchids are affected by many viruses resulting in poor growth, yield and quality, and an overall decline in population. Cymbidium mosaic virus (CymMV) is one of the common orchid viruses found in Cymbidium species but it infects different orchid genera. In this study Cymbidium aloifolium was propagated in vitro using MS medium at different strength (1.0, ½, and ¼) with or without 0.5 mg/l BAP (6-benzylaminopurine) and 0.5 mg/l NAA (Naphthalene acetic acid). To provide disease-free planting material, source plant for in vitro propagation needs to be screened for pathogenic viruses. In the present study, in vivo-grown source (mother) plants and tissue culture-derived plants of C. aloifolium were tested for CymMV virus using Double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA). All the tissue cultured plants were found to be 100% virus-free whereas the in vivo grown source plants were highly affected by CymMV virus (83.33%). The virus-free in vitro plantlets were multiplied in large scale and then acclimatized on earthen pot containing a mixture of cocopeat, litter and clay in the ratio of 3:2:1. Eighty five percent of acclimatized plantlets survived making this method an efficient mass production system for high quality virus-free C. aloifolium for commercial floriculture and germplasm preservation.

The Vanda pumila is a monopodial orchid with beautiful flowers that are native to Thailand but now found across South Asia. The immature seeds of Vanda pumila were used for in vitro culture and then the protocorms developed were used as explants for seedling development and mass propagation. Protocorms were cultured on 1/2 MS (Murashige and Skoog, 1962) medium fortified separately with Kinetin (Kn), 6-Benzyl amino purine (BAP) and Gibberellic Acid (GA3) each in different concentrations as (0.5 mg/L, 1.0 mg/L and 2.0 mg/L) well as each on each concentrations of each medium supplemented with 5% and 10% coconut water (CW) respectively. The greatest number of shoots (9.50 ± 0.29 shoots per culture) was developed on 1/2 MS medium fortified with 1.0 mg/L Kn plus 10% CW and the longest shoots (0.78 ± 0.07 cm per culture) developed on 1/2 MS medium fortified with 2.0 mg/L BAP plus 10% CW. The shoots derived from protocorms were then developed on 1/2 MS medium fortified with three different rooting hormones viz. Indole-3-acetic acid (IAA), Indole-3-butyric acid (IBA) and α-Naphthalene acetic acid (NAA), each in four concentrations (0.5 mg/L, 1.0 mg/L, 1.5 mg/L and 2.0 mg/L) as well as 1.0 mg/L of each hormone supplemented with 10% CW. The 1/2 MS medium fortified with 0.5 mg/L IAA was found to be the most effective condition for the development of maximum number of root (5 ± 0.0 roots per culture) and root length (0.93 ± 0.07 cm). Hence, the present study could be useful for standardizing the protocol for mass propagation of the endangered orchid V. pumila.

The immature seeds of Dendrobiumchryseum, asympodial epiphytic orchid with yellow flowers, were cultured in vitro, and the resultant protocorms were used as explants for seedling development. Protocorms were cultured on½ M.S. medium fortified with Kinetin (Kn), 6-Benzylaminopurine (BAP), and Gibberellic Acid (GA3) in three concentrations (0.5mg/l, 1.0mg/land 2.0 mg/l) both alone and supplemented with 5% and 10% coconut water (C.W.). The highest number of shootsofD. chryseum developed on ½ - M.S. medium fortified with 2.0mg/lofKn and10% C.W. and the longest shootsdeveloped on ½ M.S. media fortified with 1.0mg/lGA3, and 10% C.W. The shoot derived from protocorms were placed in ½ M.S. medium fortified with three different rooting hormones, Indole -3- acetic acid (IAA), Indole -3-butyric acid (IBA) and α-Naphthalene acetic acid (NAA) in different concentrations alone as well as with each 1.0mg/l hormone combined with 10% C.W. The most effective of these media was ½ M.S. medium fortified with 1.5 mg/l IAA for rooting as well as for the production of longest roots. The present study could be useful for standardizing the protocol for mass propagation of the endangered orchid Dendrobiumchryseum.