The genetic control of highly restricted branching in narrow-leafed lupin (Lupinus angustifolius L.)     

K.N. Adhikari  N.W. Galwey  M. Dracup 《Euphytica》2001,117(3):261-274

Most current cultivars of narrow-leafed lupin have an indeterminate growth habit such that vegetative growth continues while the pods are being filled, causing strong intra-plant competition for assimilates. Restricted-branching (RB) genotypes can reduce this tendency and raise the proportion of the plant's biomass going into grain. Studies on the inheritance of the RB trait showed that two spontaneous mutants, P25598 and P21227, each carried a single incompletely dominant allele conferring the trait, whereas two other spontaneous mutants, P24743 and P25582, and two induced mutants, P26021 and P21238, each carried a single recessive allele conferring the trait. The RB alleles present in P26021 and P21238 seem to be the same, and to be at the same locus as (or tightly linked to) the allele controlling the RB trait in P21227. Similarly, the genes present in P21227 and the induced mutant P25735 appear to be the same when these lines are crossed. However, they do not behave the same in crosses with P26021: thus we propose that there are at least three alleles at the same locus (or at tightly linked loci) that confer RB. Normal-branching plants that are heterozygous at an RB locus generally have fewer leaves on the uppermost branch than homozygous-normal plants. Similarly, RB plants that are heterozygous generally have fewer branchless nodes on the main stem than homozygous-RB plants. The RB trait is associated with a small but significant reduction in the number of leaves on the main stem. However, this relationship is weak and will not prevent plant breeders from selecting both early- and late-flowering RB genotypes. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Efficacy of mulching, irrigation and nitrogen applications on bottle gourd and okra for yield improvement and crop diversification     

Yih-Chi Tan  Jihn-Sung Lai  K. R. Adhikari  S. M. Shakya  A. K. Shukla  K. R. Sharma 《Irrigation and Drainage Systems》2009,23(1):25-41

An on-farm irrigation trial conducted on the upland of Chitwan valley of Nepal evaluated the amount and frequency of irrigation as well as the effect of nitrogen fertilizer and straw mulch applications on the performance of bottle gourd and okra vegetables. The experiment was laid out on split-split-plot design with fertilizer as main-plot factor, frequencies of irrigation as sub-plot factor, and amount of irrigation as sub-sub-plot factor. Data analysis revealed that frequency and amount of irrigation had a significant interaction effect on the number of nodes that emerge before the opening of the first flower in bottle gourd. Likewise, a significant effect of mulching was observed on the number of primary branches (P = 0.05). Number of nodes and primary branches both contributed to higher production of bottle gourd. Results also indicated that frequent application of higher amount of irrigation to bottle gourd could lead to reduced water productivity and suffer from yield losses. In the case of okra, low level of nitrogen application (30 kg N ha⁻¹) with low but daily watering had significantly higher yield (1,365 g plot⁻¹) than from higher level of nitrogen application (90 kg ha⁻¹) (P = 0.01). Interaction effect of all factors was also significant (P = 0.05) on the fruit yield of okra which implied greater value of smaller irrigation to contribute to increased returns to farmers by improving production level of okra in this area of Nepal  相似文献   

Assessing genetic resistance to spot blotch, <Emphasis Type="Italic">Stagonospora nodorum</Emphasis> blotch and tan spot in wheat from Nepal     

B. N. Mahto  S. Gurung  Tika B. Adhikari 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(2):249-260

Fungal leaf spot diseases of wheat (Triticum aestivum L.) in Nepal cause significant yield reduction. Although field testing has identified a few partially resistant cultivars, most wheat grown in Nepal lacks adequate resistance to leaf spot diseases. During 2009–2010, 116 local and commercial spring wheat cultivars and advanced breeding lines were selected from multi-year field experiments in Nepal and evaluated for seedling resistance to three leaf spot diseases: spot blotch, Stagonospora nodorum blotch (SNB) and tan spot races 1 and 5 (two of the most prevalent races) in the growth chambers at North Dakota State University, Fargo, ND, USA. The wheat cultivars and lines were artificially inoculated with individual pathogens or races at the two-leaf stage and disease reactions were evaluated 6 to 10 days after inoculation (DAI). Results indicated that 30%, 31%, 19% and 10% of the tested wheat cultivars and lines were resistant to spot blotch, SNB, tan spot races 1 and 5, respectively. Six advanced breeding lines (SW89-5422, BL 2127 = DANIAL88/HLB30//NL297, BL 3033, FILIN/IRENA/5/CNDO/R143//ENTE/MEXI-2/3/AE. SQUA (TAUS)/4WEAVER, GAN/AE.SQUARROSA (236)//DOY1/AE.SQUARROSA(447)/3/MAIZ/4/INQALAB91, Mayoor//TK SN1081/Ae. Squarrosa (222)/3/FCT, were resistant to spot blotch, SNB and tan spot race 1. Similarly, two wheat cultivars Chirya 3 and Chirya 7 were resistant to spot blotch, and tan spot races 1 and 5. The resistant wheat lines identified in this study represent potentially useful and untapped sources of resistance to multiple leaf spot diseases and should be utilized in wheat breeding programs in Nepal in order to develop wheat cultivars with broad-spectrum resistance.  相似文献   

Reducing Nitrogen Leaching from Agriculture: An Essential Step toward Protecting the Environment in High Rainfall Areas of Taiwan     

Keshav Raj Adhikari  Zueng-Sang Chen 《Compost science & utilization》2013,21(1):2-15

ABSTRACT

Reducing nitrogen (N) leaching from croplands is important to protect environmental quality and improve recovery of applied N. To contribute to this broader goal of nutrient management, a simple pot experiment evaluated the potential differences among urea (250 kg N ha^?1), urea+compost (125 kg N ha^?1 from urea + 125 kg N from 8 Mg ha^?1 of compost), compost (250 kg N from 16 Mg ha^?1 of compost) and a zero control (Ctrl), in terms of their effects on apparent N recovery (ANR), mineral N (N_min) leaching and soil retention of applied N. Cabbage (Brassica oleraceae L.) and corn (Zea mays L.) were grown in rotation where compost application was not repeated in the 2nd year. N_min leaching was monitored by adding 83 mm and 62 mm of water fortnightly to cabbage and corn crops, respectively for a total of 28 times in a two-year period. Combined (urea+compost) and independent (compost) treatment application retained 1.5 to 2 times higher N, and lowered 2.1 to 4.6 times N_min leaching, relative to independent (urea) application. We conclude that farmers’ practice of fertilization that has an inherent problem of N leaching for high rainfall areas in Taiwan could be improved by proper compost and urea combinations within agronomically recommended rates of N application.  相似文献   

Responses of maize × teosinte derived backcross inbred lines (BILs) to maydis leaf blight (MLB) disease     

Joshi  Anjali  Adhikari  Sneha  Singh  Narendra Kumar  Kumar  Amarjeet  Jaiswal  Jai Prakash  Pant  Usha  Singh  Rajesh Pratap 《Euphytica》2021,217(12):1-11

Euphytica - Rice growth and productivity are greatly affected by cold stress, which is likely to become more of a hindrance for high and stable rice yields. To identify cold tolerance at the...  相似文献   

Effect of Manganese and Iron on Growth and Feeding of Juvenile Giant River Prawn, Macrobrachium rosenbergii (De-Man)     

S. Adhikari    Ajaz Ahmad  Naqvi  K. C. Pani    Bindu R.  Pillai  J. K. Jena    N. Sarangi 《Journal of the World Aquaculture Society》2007,38(1):161-168

Abstract.— The effect of either manganese or iron on survival, growth, and feeding of giant river prawn, Macrobrachium rosenbergii (De-Man), juveniles was studied in two separate experiments. Survival rates of M. rosenbergii juveniles (4.58 ± 0.48 g) following 60-d exposure to 0.01 (control), 0.3, 0.6, and 1.2 mg/L of total manganese (Mn) were 100, 93.3 ± 3.4, 83.3 ± 4.3, and 83.3 ± 4.3%, respectively, while the same were 100, 83.3 ± 3.6, 73.3 ± 3.3, and 63.3 ± 4.7%, respectively, at the total iron levels of 0.02 (control), 0.32, 0.65, and 1.2 mg/L. Average daily growth of the prawn was significantly ( P  < 0.05) lower at 0.3 mg/L and higher levels of total manganese compared to control (0.01 mg/L). Average growth of the prawn exposed to 0.65 and 1.2 mg/L total iron was significantly lower ( P  < 0.05) than in control (0.02 mg/L iron) and 0.32 mg/L treatments after 60 d of exposure. Feed utilization was significantly ( P  < 0.05) reduced in M. rosenbergii juveniles exposed to 0.3 mg/L and higher levels of manganese. Feed utilization was significantly ( P  < 0.05) reduced in the prawns at all the iron treatments compared to control (0.02 mg/L iron). The accumulation of Fe and Mn was minimum in the muscle and maximum in the hepatopancreas of the prawns.  相似文献   

Bacterial blight of rice and its control in Nepal     

Tika Adhikari  Jan Leach  T. W. Mew 《Integrated Pest Management Reviews》1996,1(2):91-95

Research on Xanthomonas oryzae pv. oryzae, the bacterial blight of rice pathogen, was initiated at the Institute of Agriculture and Animal Science (IAAS) with the main objective of assessing the population structure of X. o. pv. oryzae through the use of both conventional and molecular markers in combination with virulence typing. A high DNA polymorphism was detected in the pathogen populations using different DNA probes and rep-PCR primers. Most strains were avirulent to cultivars containing the bacterial blight resistance gene Xa-21, which suggested the strategy that targets gene deployment is feasible in Nepal.  相似文献   

Susceptibility in oats to stem rust induced by co-infection with leaf rust     

K. N. Adhikari  & R. A. McIntosh 《Plant pathology》1998,47(4):420-426

Induction of susceptibility in oats to a normally avirulent pathotype of Puccinia graminis f.sp. avenae was studied in the presence of different pathotypes of P. coronata f.sp. avenae . Induction occurred on seedlings only in the presence of a virulent culture of P. coronata avenae and was not dependent on time or order of inoculation of either pathogen. This phenomenon was restricted to seedlings of lines possessing the Pg-a source of oat stem rust resistance. The specificity of induced susceptibility can be used as a valuable bioassay for screening and identifying Pg-a . Induced susceptibility occurred only at the seedling stage, and apparently provides no obstacle to the use of Pg-a as a source of stem rust resistance in oats.  相似文献   

Incentives and Community Participation in the Governance of Community Forests in Nepal     

Sunit Adhikari  Tanira Kingi  Siva Ganesh 《Small-Scale Forestry》2016,15(2):179-197

Increased participation of local users in decision-making about forests and gaining benefits from these forests are major goals of the community forestry program in Nepal. However, there is a lack of real participation in community forest governance amongst users, particularly by poor and marginalised members. By employing a mixed-method approach, this research explores the issue of participation in the governance of community forests, and in particular the role of incentives in increasing participation. A partial least square approach is undertaken to link the participation indicators to the various incentives. Access to benefits, enforcement of legal property rights and social cohesion through building of local institutions are identified as the key influential incentives that determine the effective participation of users in community forest governance. Other incentive—including income supplements, community infrastructure development or payment for environment services—are insufficient to counter the opportunity cost of participation, and hence have a weak but still significant influence on users’ decisions to participate. Power inequality due to socio-cultural norms, together with poor economic capabilities and weak bargaining power, could undermine the meaningful participation of poor and disadvantaged groups in the governance of community forests, unless the community forestry institutions are strengthened in order to be able to deal with the issues of inequitable access and restricted opportunities at the local level.  相似文献   

Zinc delivery to plants through seed coating with nano-zinc oxide particles     

Tapan Adhikari  S. Kundu  A. Subba Rao 《Journal of plant nutrition》2016,39(1):136-146

In India, zinc (Zn) has been recognized as the fourth most important yield-limiting nutrient after nitrogen (N), phosphorus (P) and potassium (K). Supplementing the zinc (Zn) requirement of agricultural crops through water soluble zinc sulfate ZnSO₄ fertilizer is a costly management option whereas, utilization of ZnO (water insoluble and a cheaper material) as a source of Zn could be an alternative cost effective option to encourage farmers for wider adoption. In this present investigation, in order to supply the requisite amount of Zn to the plants, a protocol has been developed to coat the seeds of maize (Zea mays L.), soybean (Glycine max L.), pigeon pea (Cajanas cajan L.) and ladies finger (Abelmoschus esculentus L.) with microns scale (<3 µm) and nano-scale (<100 nm) ZnO powder at 25 mg Zn/g seed and at 50 mg Zn/g seed. Different Zn sources, ethyl alcohol, and crude pine oleoresin (POR) were used for coating of seeds. The germination test carried out with coated and uncoated seeds indicated better germination percentage (93–100%) due to ZnO coating as compared to uncoated seeds (80%). Pot culture experiment conducted with coated seeds also revealed that the crop growth with ZnO coated seeds were similar to that observed with soluble Zn treatment applied as zinc sulfate heptahydrate (ZnSO₄·7H₂O) (at 2.5 ppm Zn) which is evident from the periodic SPAD reading taken after 20, 25, 30 and 45 days after sowing. Application of Zn through different sources also enhanced the auxin indole-3-acetic acid (IAA) production in plant roots, which subsequently improved the overall growth. The most important advantage of seed coating with ZnO (both micron/nano-scale) is that it did not exert any osmotic potential at the time of germination of the seed, thus, the total requirement of Zn of the crop can be loaded with the seed effectively through nano-scale ZnO particle.  相似文献