Influence of chloride and sulphate ions on soil enzymes   总被引：1，自引：0，他引：1  

R. Dinesh    G. Ramanathan  Harjit  Singh 《Journal of Agronomy and Crop Science》1995,175(2):129-133

Ammonium chloride (AC) and ammonium sulphate (AS) are commonly used nitrogen fertilizers. But the effect of chloride and sulphate ions from these fertilizers on soil enzyme activity has received scant attention. Hence, we conducted a pot culture study to assess the influence of chloride (as AC) and sulphate (as AS) on the activities of urease, amidase, phosphatase and dehydrogenase in soil using rice as the test crop. Chloride and sulphate levels were fixed at 132, 264 and 396 kg ha⁻¹ respectively. Controls were also performed. The enzymes were assayed at three stages of the crop growth viz., active tillering, panicle initiation and harvest.
The enzyme activities decreased with increasing chloride and sulphate levels; however, the degree of inhibition varied among the enzymes assayed and the nature and amounts of salts added. The inhibition may be due to the specific effects of chloride and sulphate ions on microbial growth and subsequent enzyme synthesis, osmotic desiccation leading to microbial cell lysis, and a salting-out effect modifying the ionic conformation of the active site of the enzyme protein.  相似文献   

Occurrence of aphid vector and genetic tolerance to infection by potyvirus in hot pepper     

Fekadu Marame  Chemeda Fininsa  Harjit Singh  Lemma Dessalegne  Anhild Andersson  Roland Sigvald 《Euphytica》2010,172(1):77-91

The productivity and marketable quality of hot pepper (Capsicum annuum var. annuum L.) are low in tropical regions mainly due to virus infections and lack of effective virus management strategies. The absence of effective virus management strategies could be attributed to lack of information on virus vectors and host resistance. Parental (P₁ and P₂) and progeny (F₁, B₁, B₂ and F₂) generations of five hot pepper crosses were grown in Ethiopia at three sites (Bako, Hawasa and Melkasa) to monitor number and species of potential aphid vectors, disease incidence levels with regards to natural infections by Potato virus Y (PVY) and Ethiopian pepper mottle virus (EPMV) complex, and to determine genetic tolerance of the crop to the viruses. Disease incidence was assessed before the flowering stage of the crop plants using visible disease symptoms due to infections by PVY and EPMV. The serological tests revealed presence of symptomless genotypes of the crop to the virus infections. Aphid species potentially transmitting the viruses, such as Acyrthosiphon pisum (Harris), Aphis fabae (Scopoli), and Myzus persicae (Sulzer), were identified from specimens caught by yellow water traps. The highest number of aphids from yellow water traps was recorded at a dense foliage growth stage of the crop at Melkasa. Highly significant variation was observed among generations of the five crosses in response to infections by PVY and EPMV complex. The most susceptible parents had the levels of disease incidences ranging from 80 to 90%, whereas their progenies had only below 30% incidence levels. The most tolerant parent remained symptomless to the natural infections of PVY- and EPMV-complex. Incidence levels in progenies of a cross from the most susceptible and tolerant parents remained below 20%. Based on serological test, the proportion of PVY-positive plants ranged from 0 to 75% and of EPMV-positive plants from 0 to 25%, with 0 to 17% co-infection by the two viruses. Availability of virus sources in the vicinity, efficiency of aphids in vectoring, weather conditions during the growth period, genetic tolerance and the growth stage of the crop affected natural infection by PVY- and EPMV-complex. Exploitation of the genetic potential of introduced elite genotypes and their progenies along with breeding elite local cultivars for resistance and excluding aphid vectors at young (seedling) stage of the crop plants could be helpful for minimizing losses in yield and quality of hot pepper due to infections by PVY- and EPMV-complex.  相似文献   

Effect of micronutrient supplementation around calving on the plasma cortisol levels of Murrah buffaloes and Sahiwal and Karan Fries cows     

Ajay Kumar Dang  Manu Jamwal  Mandheer Kaur  Shiv Prasad Kimothi  Shashi Pal  Kalyan De  Mohsin M. Pathan  Dilip K. Swain  Sushil K. Mohapatra  Suman Kapila  Rajeev Kapila  Harjit Kaur  Ashok K. Mohanty  Bukkaraya S. Prakash 《Tropical animal health and production》2013,45(4):1047-1050

Micronutrients when fed around peripartum may reduce the stress induced by cortisol. With this objective, 24 Sahiwal (SW) and 24 Karan Fries (KF) cows and 24 Murrah (Mu) buffaloes were taken and divided into four groups of six each. Vitamin E (VE), zinc (Zn) and copper were supplemented from 30 days pre- to 30 days postcalving in groups 1, 2 and 3. Animals without supplementation served as control. Blood sampling was done on days 30, 15, 7 and 3 precalving; at calving; and on days 3, 7, 15 and 30 postcalving. Plasma cortisol levels were measured by ELISA. Supplementation of VE and Zn significantly (P?<?0.05) reduced plasma cortisol levels at calving and at 30 days postcalving. KF cows exhibited best results with VE, whereas SW cows and Mu buffaloes responded best to Zn. Copper increased the peripartum cortisol levels. Reduction in cortisol levels may help in keeping the animal healthy and stronger to fight immuno-suppression generally observed around the period of peripartum.  相似文献   

STMS markers for grain protein content and their validation using near-isogenic lines in bread wheat   总被引：5，自引：0，他引：5  

Harjit  -Singh  M. Prasad    R. K. Varshney    J. K. Roy    H. S. Balyan    H. S. Dhaliwal  P. K. Gupta   《Plant Breeding》2001,120(4):273-278

The present study, undertaken as a continuation of an earlier study on quantitative trait loci (QTL) analysis of grain protein content (GPC) in bread wheat (Prasad et al. 1999), includes the following: (1) identification of an additional molecular marker associated with GPC; (2) development of near‐isogenic lines (NILs) for high GPC; and (3) the use of three sets of NILs (a total of 10 NILs) to validate the two available markers linked with QTL for GPC. A total of 114 sequence‐tagged microsatellite site (STMS) primer pairs (that were not used in the previous study) were used for detection of polymorphism between the two parents (PH132, with high GPC; WL711, with low GPC) of a mapping population of 100 recombinant inbred lines (RILs). A total of 95 primer pairs gave amplification products, of which only 30 detected reproducible polymorphism between the parental genotypes. Bulked segregant analysis was conducted using these 30 primers on two bulks (each comprising eight RILs) representing the two extremes of the normal distribution. A solitary primer pair (WMC415) showed association with GPC, which was further confirmed through selective genotyping. Subsequently, 100 RILs were genotyped. A single‐marker linear regression analysis showed significant association between the marker WMC415 and GPC, thus identifying a quantitative trait locus (designated as QGpcccsu‐5A1), which explained 6.21% of the variation for GPC among the RILs. The above STMS marker, together with the STMS marker (WMC41) identified earlier, explains approximately 25% of the variation for GPC. In order to conduct validation of the above two available markers, 10 NILs were developed for high GPC using two genotypes (WL711 and HD2329) with low GPC as recipient parents and another two genotypes (PH132 and PH133) with high GPC as donor parents. NIL 2233 (with 11.7% GPC), derived from HD2329, when tried with WMC41 gave a characteristic amplification profile similar to that of its donor parent PH132, and NIL 2215 (with 11.9% GPC) derived from WL711, when tried with WMC415 gave an amplification profile that resembled its donor parent PH133. The remaining eight NILs with high GPC gave patterns similar to those of their corresponding recipient parents with both the markers, suggesting that either the QTL, other than those associated with the above markers, were actually transferred from the donor parents and contributed to high GPC in these NILs or that recombination had occurred between the markers identified and the corresponding QTL. Thus, the marker validation conducted using NILs, while demonstrating the utility of these two microsatellite markers for use in marker‐assisted selection in plant breeding, also suggested that many more QTL exist that would need to be identified using closely linked molecular markers.  相似文献   

A microsatellite marker linked to leaf rust resistance transferred from Aegilops triuncialis into hexaploid wheat   总被引：1，自引：0，他引：1  

M. Aghaee-Sarbarzeh  Harjit  -Singh H. S. Dhaliwal 《Plant Breeding》2001,120(3):259-261

Aegilops triuncialis (UUCC) is an excellent source of resistance to various wheat diseases, including leaf rust. Leaf rust‐resistant derivatives from a cross of a highly susceptible Triticum aestivum cv.‘WL711’ as the recurrent parent and Ae. triuncialis Ace.3549 as the donor and with and without a pair of acrocentric chromosomes were used for molecular tagging. The use of a set of sequence tagged microsatellite (STMS) markers already mapped to different wheat chromosomes unequivocally indicated that STMS marker gwm368 of chromosome 4BS was tightly linked to the Ae. triuncialis leaf rust resistance gene transferred to wheat. The presence of the Ae. Triuncialis‐specific STMS gwm368 homoeoallele along with the non‐polymorphic 4BS allele in the rust‐resistant derivatives with and without the acrocentric chromosome indicates that the resistance has been transferred from the acrocentric chromosome to either the A or the D genome of wheat. This alien leaf rust resistance gene has been temporarily named as LrTr.  相似文献   

Genetic Control of High Protein Content and Its Association with Bread-Making Quality in Wheat     

M. Garg  Harjit Singh  Harinder Kaur  H. S. Dhaliwal 《Journal of plant nutrition》2013,36(8):1357-1369

ABSTRACT

A population of recombinant inbred lines (RILs) developed from a cross of Triticum aestivum cvs. WL711 and PH132 using the single-seed descent method was used to investigate the genetics of high protein content and its contribution to bread-making quality. Four-year data on protein content of parents and 124 RILs suggested that the difference in protein content between the two parents was controlled by two major genes with an additive effect. The individual gene gave intermediate protein content. Seven RILs with high protein content and without any yield penalty were selected, multiplied, and investigated for various milling, dough, and bread-making characteristics. PH132 and all seven selected RILs had higher protein content, higher sodium dodecyl sulphate (SDS) sedimentation value, longer dough development time, a lower mixing tolerance index, higher stability, and better loaf volume and loaf quality than the bread wheat cultivars WL711 and PBW343. High molecular weight (HMW) glutenin subunit composition of various high-protein RILs indicated a recombination of parental protein subunits. “2?” coded by Glu-A1 locus, 17 + 18 subunits coded by Glu-B1 locus, and “5 + 10” coded by Glu-D1 locus were predominant. One of the selected RILs, T-74, possessing 2 + 12 at Glu-D1 locus, also had superior bread-making quality, indicating that grain-protein content above a certain minimum value is a relatively more important determinant of bread-making quality than HMW glutenin subunits 5 + 10.  相似文献   

Variation in partial resistance to barley leaf rust (Puccinia hordei) and agronomic characters of Ethiopian landrace lines     

Getaneh Woldeab  Chemeda Fininsa  Harjit Singh  Jonathan Yuen  Jose Crossa 《Euphytica》2007,158(1-2):139-151

An inventory of 481 lines derived from 12 Ethiopian barley (Hordeum vulgare L.) landraces and the checks was made for partial resistance to Puccinia hordei under greenhouse and field conditions at Adet, Ambo and Sinana Agricultural Research Centers in 2003 and 2004 cropping seasons in Ethiopia. The experiments were laid out in a triple lattice design. Each plot consisted of two rows of 1–m long with spacing of 0.20 m between rows. The overall mean leaf rust epidemics varied from area under disease progress curve (AUDPC) of 86 to 1,835. The disease was as high as AUDPC 1,378 on the susceptible check L94. Highly significant variations were recorded between and within the landraces/lines in leaf rust incidence, severity, days to heading, plant height, thousand seed weight and yield. Similarly, the variations between and within barley groups from three altitude areas and three ear-types were significant. Landraces 1686, 3255, 3262 and 3783 had the least and landraces 219900, 3975 and 3980 had the highest leaf rust severity. Of the 481 lines tested, 413 (86%) had significantly lower disease than the susceptible check, but not than the partial resistant check Vada. In contrast, the yields were more for lines with less disease than for those with high. The frequency of resistant landraces/lines was more in altitude 2,301–2,500 m, and irregular and two rows ear-types than in lower altitude areas and six rows ear-type. Nevertheless, the correlation and regression analysis revealed the adverse effect of the disease in the yields of barley. The 413 lines with high infection types at seedling stage and lower AUDPC under field conditions possess partial resistance to leaf rust.  相似文献