Water use efficiency of irrigated wheat in the Tarai region of India

Experiments were conducted during the winter seasons of 1983–1984 and 1984–1985 to identify suitable irrigation regimes s for wheat grown after rice in soils with naturally fluctuating shallow water table (SWT) at a depth of 0.4 to 0.9 m and medium water table (MWT) at a depth of 0.8 to 1.3 m. Based on physiological stages, the crop was subjected to six irrigation regimes viz., rainfed (I₀); irrigation only at crown root initiation (I₁); at only crown root initiation and milk (I₂); at crown root initiation, maximum tillering and milk (I₃); at crown root initiation, maximum tillering, flowering and milk (I₄); and at crown root initiation, maximum tillering, flowering milk and dough (I₅). Tube-well water with an EC <0.4 dsm^–1 was used for irrigation. Based on 166 mm effective precipitation during the cropping season, 1983–1984 was designated as a wet year and 1984–1985 with 51 mm as a dry year. The change in profile soil water content W (depletion) in the wet year was less (23%) under SWT and 10% under MWT as compared to the dry year. The ground water contribution (GWC) to evapotranspiration (ET) was 58% under SWT and 42% under MWT conditions in both the years. The GWC in the wet year was 20% under SWT and 23% under MWT. Of the total net water use (NWU), about 85% was ET and 15% drainage losses. The NWU was highest (641 and 586 mm) in I₅ under SWT and MWT conditions, respectively, but not the yield (5069 kg ha^–1). Compared to I₅, NWU in I₂ treatment decreased by 10% in the wet and 25% in the dry year. A similar trend was observed in the I₃ treatment under MWT condition. However, there was no statistically significant difference between yields of the I₁ to I₅ treatments of either water table depth during the wet year. This was also true during the dry year for the I₂ to I₅ treatments. Under SWT, in I₂, the grain yield was 5130 kg ha^–1 and under I₃ regime, 5200 kg ha^–1. Under MWT in I₃, the yield was 5188 kg ha^–1 and under I₄ regime, 5218 kg ha^–1. Thus it appears that in the Tarai region where the water table remains shallow (<0.9 m) and medium (<1.3 m) for most of the wheat growing season applications of more than 120 and 180 mm irrigation under SWT and MWT conditions, respectively were not necessary. Irrigation given only at crown root initiation and milk stages under shallow water table conditions, and at crown root initiation, maximum tillering and milk stages under medium water table conditions, appears to be as effective as frequent irrigations.     

Population genetic structure and diversity of high value vulnerable medicinal plant <Emphasis Type="Italic">Acorus calamus</Emphasis> in India using RAPD and chloroplast microsatellite markers

Acorus calamus is a highly valued medicinal plant with global distribution used in several drugs of health care systems. We evaluated the genetic diversity and population structure of 50 populations of A. calamus from different geographical regions in India through RAPD and chloroplast microsatellite markers. From the total screened 82 RAPD primers and 18 cpSSR primers, 10 RAPD and nine cpSSRs were found polymorphic. The selected 10 RAPD primers produced a total of 96 reproducible bands, out of which 65 wer...     

Effect of nitrogen and phosphorus application on agricultural soil food webs

Aim of the present research is to investigate the effect of nitrogen (N) and phosphorus (P) on soil food webs (microbes, nematodes and microarthropods) trophic interactions in agriculture ecosystems. A complete randomized block design experiment of N and P fertilization was initiated in 2010 with four treatments: (1) P-addition, (2) N-addition, (3) NP-addition and (4) control. After 4 years of fertilization, compared with control, N-addition had a negative effect on microarthropods and clarify indirectly by significantly (P < 0.05) increasing soil total nitrogen (0.37 g kg^?1) and available nitrogen (20.03 mg kg^?1). The reduction in microarthropods resulted significant (P < 0.05) increase in bacterivores and fungivores feeding on bacteria and fungi, an example of top-down control. P-addition had indirect negative effects on microarthropods by means of significantly (P < 0.05) increasing soil total phosphorus (0.62 g kg^?1) and available phosphorus (24.17 mg kg^?1), aggravated fungivores feeding on fungi and strengthened top-down control. NP-addition significantly (P < 0.05) increased total microbial biomass, nematodes and microarthropods and resulted in bottom-up control. These results suggested that top-down effects were the dominant force in N- or P-addition treatments. NP-addition strengthened bottom-up control by enriching food resource. Unbalance fertilization could pose adverse on agricultural soil ecosystem and yield potential of crops.     

Foliar spray of mineral nutrients enhanced the growth,seed yield,and quality in onion (Allium cepa L.) cv. Pusa Riddhi

The present experiment was conducted to investigate the effect of foliar spray of mineral nutrients on plant growth, seed yield, and quality attributes in onion cv. Pusa Riddhi at SPU, IARI, New Delhi during rabi 2013–14 and 2014–15. The experiment consisted of 16 treatments comprised of boron, zinc, calcium, and magnesium laid out in a completely randomized block design with two replications. The study revealed that the foliar zinc spray (625 g ha^?1) produced higher seed scape height (105.35 cm) along with lower disease incidence (8.50%) than the other treatments. Whereas, higher number of seed scapes plant^?1 (11.20) and productive seed scapes plant^?1 (8.58) were observed in T₁₀ (500 g ha^?1) and combined spray of B + Zn + Ca (T₁₄), respectively. The flowering traits, viz., umbellates umbel^?1 (642.45), productive umbellates umbel^?1 (579.35), and umbel diameter (7.38cm) were significantly (p ≤ 0.05) higher in T₁₅ than other treatments. Similarly, higher seed yield and seed quality attributes were also observed in combined application of all minerals treatment (T₁₅).     

A stable serine protease, wrightin, from the latex of the plant Wrightia tinctoria (Roxb.) R. Br.: purification and biochemical properties

Today proteases have become an integral part of the food and feed industry, and plant latex could be a potential source of novel proteases with unique substrate specificities and biochemical properties. A new protease named "wrightin" is purified from the latex of the plant Wrightia tinctoria (Family Apocynaceae) by cation-exchange chromatography. The enzyme is a monomer having a molecular mass of 57.9 kDa (MALDI-TOF), an isoelectric point of 6.0, and an extinction coefficient (epsilon1%280) of 36.4. Optimum activity is achieved at a pH of 7.5-10 and a temperature of 70 degrees C. Wrightin hydrolyzes denatured natural substrates such as casein, azoalbumin, and hemoglobin with high specific activity; for example, the Km value is 50 microM for casein as substrate. Wrightin showed weak amidolytic activity toward L-Ala-Ala-p-nitroanilide but completely failed to hydrolyze N-alpha-benzoyl- DL-arginine-p-nitroanilide (BAPNA), a preferred substrate for trypsin-like enzymes. Complete inhibition of enzyme activity by serine protease inhibitors such as PMSF and DFP indicates that the enzyme belongs to the serine protease class. The enzyme was not inhibited by SBTI and resists autodigestion. Wrightin is remarkably thermostable, retaining complete activity at 70 degrees C after 60 min of incubation and 74% of activity after 30 min of incubation at 80 degrees. Besides, the enzyme is very stable over a broad range of pH from 5.0 to 11.5 and remains active in the presence of various denaturants, surfactants, organic solvents, and metal ions. Thus, wrightin might be a potential candidate for various applications in the food and biotechnological industries, especially in operations requiring high temperatures.     

Selection indices for improving selection efficiency in Indian mustard

In Indian mustard (Brassica juncea L. Czern & Coss), a major oilseed brassica crop, oil yield is the ultimate trait of economic value, which is determined by seed yield (SY) and oil content (OC). SY, the end product of many complex biological processes, is influenced by many traits, such as plant height (PH), branch number, siliqua number, seed weight, seed size and pod length. It is difficult to accurately select for high-yielding genotypes based exclusively on SY, neglecting other yield-determining traits in commercial breeding programs. Therefore, it is desirable for breeders to simultaneously improve several traits of economic importance, most of which are quantitative in nature. The purpose of the present study was to develop selection indices for simultaneous selection of multiple quantitative traits to enhance selection efficiency of the mustard breeding program of Punjab Agricultural University (PAU) located in Abohar, Punjab. A set of 487 diverse mustard genotypes, comprising germplasm accessions of Indian and European origin, advanced breeding lines, landraces, and cultivars, was evaluated using an alpha lattice design for 2 years (2015–16 and 2016–17) at the Regional Research Station of PAU, Abohar, District Fazilka (the major mustard-growing region of the Punjab state). Data on PH, main shoot length (MSL), number of primary branches (NPB), number of secondary branches (NSB), number of siliquae on main shoot (NSMS), siliqua length (SL), number of seeds per pod (NSP), 1000-seed weight (TSW), SY on a plot basis and OC were recorded. To compute selection indices, economic weights, as determined via path coefficient analysis, were assigned to major yield-determining traits. Out of eight recorded agronomic traits, four traits, viz., NSMS, TSW, NSB and NPB, had larger direct effects on SY than other traits, and hence were assigned relative economic weights of 0.60, 0.20, 0.12 and 0.08, respectively. Selection indices were computed using different combinations of traits via Kang_SASPath computer program. When seven traits were used in a selection index (PH, NPB, NSB, NSMS, SY, TSW and MSL; or PH, NPB, NSB, NSMS, SY, TSW and OC), expected genetic advance (GA)at 5% selection intensity was about the same (9.55; selection efficiency or SE = 163% compared with selection based on SY alone).The GA was 9.46 (SE = 161%)for five traits, viz., NPB, NSB, NSMS, SY and TSW; and 9.30 (SE = 159%)for four traits, viz., NPB, NSB, NSMS, and TSW. These GAs were compared with the GA for SY only, which was 5.90 (benchmark; SE = 100%). We concluded that simultaneous selection based on multiple traits was always more efficient than selection based on SY alone. As there was only a small difference between the GA based on four traits (SE = 161%) and GA based on seven traits (SE = 163%), we suggest that mustard breeders use the parsimonious combination of four traits, viz., NPB, NSB, NSMS, and SY, to enhance SY and, consequently, oil yield in mustard.     

Chemical composition,antioxidant activity and GC-MS analysis of juice and peel oil of grapefruit varieties cultivated in India

Citrus family especially Grapefruit, has attained considerable attention due to the presence of a number of essential components that have cardiovascular and anti-hypertensive properties. The juice and essential oil extracted from eight recently released grapefruit cultivars were used to study physicochemical and antioxidant properties. The total soluble solids (TSS), titratable acidity (TA) and pH of juice samples extracted from various grapefruit varieties differed significantly. The refractive index, specific gravity and optical rotation values for the oil varied from 1.473 to 1.396, 0.863 to 0.847 and +93 to +86, respectively. The percent 2,2-diphenyl-1-picrylhydrazyl radical activity (% DPPH activity) and ferric reducing antioxidant power (FRAP) values for grapefruit juice and peel oil varied from 24.06 to 18.79, 2.91 to 1.44 mmol g^–1 and 84.87 to 74.73, 7.76 to 5.73 mmol g^–1, respectively. There were significant differences in physicochemical, antioxidant properties and volatile profiles of extracted juice and oil. The oil exhibited higher DPPH and FRAP values than the juice. Among different components identified which accounted for over 99% of the volatile fraction, limonene, myrcene, and benzopyran were major components in all oil samples.