Hybridization and in vitro culture of an orchid hybrid Ascocenda ‘Kangla’     

Rajkumar Kishor  P.S. Sha Valli Khan  G.J. Sharma 《Scientia Horticulturae》2006

The present study focuses on hybridization program involving two species belonging to two different vandaceous genera, viz., Ascocentrum ampullaceum (Roxb.) Schltr. var. auranticum, a narrow endemic orchid of Manipur and Vanda coerulea Griff., an endangered orchid of Appendix I of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), to synthesize the primary hybrid genus with intermediate and improved characters in the F₁ generation. Observations on the crossability in the present bigeneric cross between V. coerulea and A. auranticum had been achieved with 60% success when V. coerulea was taken as female parent. Murashige and Skoog (MS) basal medium at half-strength was effective for the development of the hybrid seedlings of V. coerulea × A. auranticum followed by Vacin and Went (VW) and Knudson C (KC) media. The best response of seedling growth was observed on MS medium at half-strength supplemented with 2.3 μM kinetin + 0.5 μM α-naphthalene acetic acid with maximum shoot height (2.7 cm), leaf number (4.6) and root number (4.1) after 150 days of inoculation. The survival percentage and growth performance of the seedlings were found to be higher (80% survival) in potting substrate consisting of brick:charcoal in the ratio 2:1 mulched with moss (Sphagnum sp.) than in potting substrate consisting of brick:charcoal:tree fern in the ratio 2:1:1. The first flowering was observed in the hybrid seedlings of V. coerulea × A. auranticum after 2 years of transfer to the ex vitro environment. Morphologically, the flowers differed from that of the parents clearly showing the success of the hybridization experiment. Registration of the hybrid has been made with the Royal Horticultural Society with the nomenclature Ascocenda ‘Kangla’ (No. T128725).  相似文献   

Effect of prolonged exposure to exogenous melatonin on the onset and end of the breeding season and on the growth rate of ewe lambs     

R Nowak  R R Rajkumar  G E Webley  R G Rodway 《The British veterinary journal》1990,146(1):17-23

The effect of prolonged exposure to exogenous melatonin on the reproductive status and growth rate of ewe lambs was investigated. Ewe lambs (born late March) were given intravaginal melatonin implants on 4 July (group J, n = 10) during anoestrus, or 20 December (group D, n = 10) during the breeding season. A third group (group C, n = 7) received empty implants on 4 July. Plasma progesterone concentrations were used to assess reproductive status. In the control group cyclic ovarian activity began on November 15 +/- 4 days, and ceased on January 28 +/- 8 days. In group J the onset of the breeding season was advanced by 4.9 weeks (occurring on October 12 +/- 4 days; P less than 0.001). The onset of anoestrus was also advanced in this group with 9 out of 10 of the ewes ceasing ovarian activity at least 3.4 weeks in advance of the control ewes (P less than 0.01). In contrast the timing of anoestrus was unchanged in group D, occurring on February 14 +/- 6 days. Melatonin treatment of ewe lambs from early July had no effect on growth rate, whereas treatment from mid-December had a depressive effect. Ewes therefore become refractory to the inductive effects of exogenous melatonin after long-term exposure. The results are consistent with the view that photorefractoriness is due to changes in the processing rather than the generation of the melatonin signal.  相似文献   

Neoplasia in the Indian oil sardine, Sardinella longiceps (Valenciennes), and the great barracuda, Sphyraena barracuda (Edwards), from the south-east coast of India     

Gopalakrishnan A  Maran BA  Puvanendran V  Rajkumar M  Balasubramanian T  Ferguson HW 《Journal of fish diseases》2011,34(11):881-885

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Clonal propagation of triploid <Emphasis Type="Italic">Acorus calamus</Emphasis> Linn. Using dual-phase culture system     

Ningthoujam Sandhyarani  Rajkumar Kishor  Gurumayum Jitendra Sharma 《Journal of Crop Science and Biotechnology》2011,14(3):213-217

Acorus calamus is an important medicinal plant which has been used in Indian traditional medicine since time immemorial. Various bioactive molecules, viz., acorin, α- and β-asarone, asaryldehyde, caryophylene, isoasarone, methylisoeugenol, and safrol have been isolated from this plant. However, the use of this plant for medicinal purpose has been recently banned due to the high toxic property of β-asarone. The triploid Acorus calamus is reported to be low in β-asarone content and thus found to be the ideal raw material for medicinal use. The present investigation represents our finding for successful in vitro clonal propagation of the elite triploid accessions of Acorus calamus for mass propagation. In the dual-phase culture system consisting of agar-solidified Murashige and Skoog medium overlaid by liquid fraction of the same medium, maximum multiple shoot induction was favored by supplementation of α-naphthaleneacetic acid (0.5 mg L⁻¹) and 6-benzylaminopurine (2.0 mg L⁻¹). In vitro rooting of the microshoots was maximum in the medium supplemented with indolebutyric acid at 2.0 mg L⁻¹. The well-rooted microshoots could be successfully hardened and transplanted in the field. This result can be reproduced and is a viable protocol for successful clonal propagation of the seedless triploid Acorus calamus for conservation and sustainable development.  相似文献   

Fertility of ewes given either melatonin or progestogen sponges     

R R Rajkumar  C M Argo  R G Rodway 《The Veterinary record》1989,124(9):215-217

The administration of melatonin via intravaginal sponges is an effective method of advancing the breeding season in ewes. In the present study the fertility of melatonin-treated ewes has been compared with that of ewes induced to ovulate by conventional treatment. On June 25, 15, 15-month-old ewes (group 1) were given intravaginal implants containing melatonin in silastic tubing. On August 8, 13 similar ewes (group 2) were given Veramix sponges which were removed 12 days later, when they were given 500 iu pregnant mare's serum gonadotrophin (PMSG). Two intact raddled rams were introduced to the combined groups on August 21. The mean date of mating was September 3 +/- 1.5 for group 1 and August 21 +/- 0.2 for group 2 ewes. All the ewes in group 1 and 10 in group 2 (77 per cent) were mated. All the ewes were slaughtered approximately 50 days after mating and their reproductive tracts removed. The mean ovulation rates were 2.1 and 2.3 in groups 1 and 2, respectively. The results indicate that conception rates of 87 per cent and 61.5 per cent of ewes put to the ram were obtained in the melatonin-treated and PMSG-treated groups, respectively. At slaughter the melatonin-treated group were found to have a mean of 1.47 live fetuses per ewe put to the ram and the PMSG-treated group a mean of 1.08. It can therefore be concluded that melatonin implantation is an effective method for the advancement of seasonal breeding in anoestrous sheep, and that the fertility achieved is at least as good as that given by conventional progestogen-PMSG treatment.  相似文献   

Incidence of goiter in goats     

S S Rajkumar 《The Indian veterinary journal》1970,47(2):185-187

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Evaluation of two Indian native chicken breeds for reproduction traits and heritability of juvenile growth traits     

Haunshi S  Shanmugam M  Padhi MK  Niranjan M  Rajkumar U  Reddy MR  Panda AK 《Tropical animal health and production》2012,44(5):969-973

The present study was conducted to evaluate two Indian native chicken breeds, namely, Aseel and Kadaknath for fertility, hatchability, genetic parameters of juvenile growth traits, and semen quality traits at the onset of sexual maturity. The fertility was similar in Aseel (86.96%) and Kadaknath (85.15%); however, a relatively higher hatchability was observed in Kadaknath (77.94%) than Aseel (70.74%). Heritability estimates of body weights at 4 weeks of age were almost similar in Aseel (0.37) and Kadaknath (0.39), while the estimate of body weight at 6 weeks of age was higher in Aseel (0.42) than Kadaknath (0.31). The heritability estimate of shank length at 6 weeks of age was lower in Aseel (0.16) compared to Kadaknath (0.35). The age at first egg in the flock was comparable in Aseel (148 days) and Kadaknath (150 days). Aseel breed with significantly (P ≤ 0.001) higher body weight, absolute and relative testes weights had significantly higher semen volume (P ≤ 0.05) and sperm motility (P ≤ 0.01) but had lower seminal plasma cholesterol level (P ≤ 0.05) as compared to Kadaknath. It can be concluded that there is a scope for genetic improvement of these two native breeds for juvenile growth traits since heritability estimates of these traits were relatively high.  相似文献   

Seroprevalence of Peste des petits ruminants in cattle and buffaloes from Southern Peninsular India   总被引：1，自引：1，他引：0  

Balamurugan V  Krishnamoorthy P  Veeregowda BM  Sen A  Rajak KK  Bhanuprakash V  Gajendragad MR  Prabhudas K 《Tropical animal health and production》2012,44(2):301-306

This study describes seroprevalence of Peste des petits ruminants (PPR) in cattle and buffaloes carried out during the period 2009–2010 using the randomly collected serum samples from different parts of Southern peninsular India. The report presents the results of PPR virus (PPRV)—specific antibodies in situations where either the subclinical or inapparent or non-lethal infection was there in cattle and buffaloes. A total of 2,548 serum samples [cattle = 1,158, buffaloes = 1,001, sheep = 303 and goat = 86] were collected and screened for PPRV antibodies by using a PPR monoclonal antibody-based competitive ELISA kit. Analysis of 2,159 serum samples indicates an overall 4.58% prevalence of PPRV antibody in cattle and buffaloes. The presence of PPRV-specific antibodies demonstrates that cattle and buffaloes are exposed to PPR infection naturally, and the transmission mode may be direct or indirect. Further, it implies the importance of bovines as subclinical hosts for the virus besides widespread presence of the disease in sheep and goats in the country.  相似文献   

Marker‐assisted introgression of rare allele of β‐carotene hydroxylase (crtRB1) gene into elite quality protein maize inbred for combining high lysine,tryptophan and provitamin A in maize     

Rajat Goswami  Rajkumar Uttamrao Zunjare  Suphiya Khan  Aanchal Baveja  Vignesh Muthusamy  Firoz Hossain 《Plant Breeding》2019,138(2):174-183

Vitamin A deficiency in humans is a widespread health problem. Quality protein maize (QPM) is a popular food rich in lysine and tryptophan, but poor in provitamin A (proA). Here, we report the improvement of an elite QPM inbred, HKI1128Q for proA using marker‐assisted introgression of crtRB1‐favourable allele. HKI1128 was one of the parental lines of three popular hybrids in India and was converted to QPM in our earlier programme. Severe segregation distortion for crtRB1 was observed in BC₁F₁, BC₂F₁ and BC₂F₂. Background selection by 100 SSRs revealed mean recovery of 91.07% recurrent parent genome varying from 88.78% to 93.88%. Across years, introgressed progenies possessed higher mean β‐carotene (BC: 9.22 µg/g), β‐cryptoxanthin (BCX: 3.05 µg/g) and provitamin A (proA: 10.75 µg/g) compared to HKI1128Q (BC: 2.26 µg/g, BCX: 2.26 µg/g and proA: 3.38 µg/g). High concentration of essential amino acids, viz. lysine (mean: 0.303%) and tryptophan (0.080%) in endosperm, was also retained. Multi‐year evaluation showed that introgressed progenies possessed similar grain yield (1,759–1,879 kg/ha) with HKI1128Q (1,778 kg/ha). Introgressed progenies with higher lysine, tryptophan and proA hold immense potential as donors and parents in developing biofortified hybrids.  相似文献   

Identifying important biophysical and social determinants of on-farm tree growing in subsistence-based traditional agroforestry systems   总被引：1，自引：1，他引：0  

Kamal Kishor Sood  C. Paul Mitchell 《Agroforestry Systems》2009,75(2):175-187

Many expert-designed agroforestry projects enunciated in 1970s around the world, particularly in the developing countries, had uneven success due to inadequate adoption or abandonment after adoption. There are many empirical studies on factors affecting on-farm tree cultivation mainly where expert-designed agroforestry programmes were introduced but lacking in case of traditional agroforestry. Moreover, the concern to identify key factors influencing on-farm tree growing is gaining importance. The present study identifies key factors in on-farm tree growing based on investigation of traditional agroforestry using logistic regression approach. The study is based on household survey of 401 households located in Indian Western Himalaya. The factors affecting on-farm tree growing were grouped into: biophysical (included land use and infrastructural aspects) and social. Models predicting on-farm tree growing for each category were developed and key factors affecting on-farm tree growing in the respective category were identified. A composite model was also developed by combining biophysical and social factors. In the present study, farm size, agroclimatic zone, soil fertility, mobility and importance of tree for future generations respectively were the key factors which influenced tree growing. In contrast to many previous studies which considered either biophysical or social factors, the composite model in the present study reveals that both biophysical and social factors are simultaneously important in motivating the farmers to grow trees on their farms in traditional agroforestry. Moreover, the present study open vistas for using farmers’ experience and knowledge of adoption of agroforestry to stimulate on-farm tree growing. The wider implication of the study is that biophysical as well as social variables should be considered together in designing suitable agroforestry systems in various parts of the world.  相似文献