Ishwar Singh Solanki

Molecular mapping of the grain iron and zinc concentration, protein content and thousand kernel weight in wheat (Triticum aestivum L.)

Genomic regions responsible for accumulation of grain iron concentration (Fe), grain zinc concentration (Zn), grain protein content (PC) and thousand kernel weight (TKW) were investigated in 286 recombinant inbred lines (RILs) derived from a cross between an old Indian wheat variety WH542 and a synthetic derivative (Triticum dicoccon PI94624/Aegilops squarrosa [409]//BCN). RILs were grown in six environments and evaluated for Fe, Zn, PC, and TKW. The population showed the continuous distribution for all the four traits, that for pooled Fe and PC was near normal, whereas, for pooled Zn, RILs exhibited positively skewed distribution. A genetic map spanning 2155.3cM was constructed using microsatellite markers covering the 21 chromosomes and used for QTL analysis. 16 quantitative trait loci (QTL) were identified in this study. Four QTLs (QGFe.iari-2A, QGFe.iari-5A, QGFe.iari-7A and QGFe.iari-7B) for Fe, five QTLs (QGZn.iari-2A, QGZn.iari-4A, QGZn.iari-5A, QGZn.iari-7A and QGZn.iari-7B) for Zn, two QTLs (QGpc.iari-2A and QGpc.iari-3A) for PC, and five QTLs (QTkw.iari-1A, QTkw.iari-2A, QTkw.iari-2B, QTkw.iari-5B and QTkw.iari-7A) for TKW were identified. The QTLs together explained 20.0%, 32.0%, 24.1% and 32.3% phenotypic variation, respectively, for Fe, Zn, PC and TKW. QGpc.iari-2A was consistently expressed in all the six environments, whereas, QGFe.iari-7B and QGZn.iari-2A were identified in two environments each apart from pooled mean. QTkw.iari-2A and QTkw.iari-7A, respectively, were identified in four and three environments apart from pooled mean. A common region in the interval of Xgwm359-Xwmc407 on chromosome 2A was associated with Fe, Zn, and PC. One more QTL for TKW was identified on chromosome 2A but in a different chromosomal region (Xgwm382-Xgwm359). Two more regions on 5A (Xgwm126-Xgwm595) and 7A (Xbarc49-Xwmc525) were found to be associated with both Fe and Zn. A QTL for TKW was identified (Xwmc525-Xbarc222) in a different chromosomal region on the same chromosome (7A). This reflects at least a partly common genetic basis for the four traits. It is concluded that fine mapping of the regions of the three chromosomes of A genome involved in determining the accumulation of Fe, Zn, PC, and TKW in this mapping population may be rewarding.

Central Wheat Hs562'-A High Yielding Wheat Variety for Timely Sown Production Conditions of Northern Hill Zone

Dharam Pal1*, Madhu Patial1, KV Prabhu2, J Kumar1,7, Santosh Watpade1, RN Yadav3, Sanjay Kumar2, RK Sharma2, GP Singh2,8, Rajbir Yadav2, Vinod2, Anju M Singh2, SV Sai Prasad4, IS Solanki6,9, M Sivasamy5, JB Sharma2, PK Singh2, Neelu Jain2, Niharika Mallik2, Kiran Gaikwad2, Tapas Ranjan Das6, Vikas5, Jaya Prakash5, JB Singh2, Divya Ambati4, Vaibhav Singh2, AN Mishra4, Shivadhar2 and Ajay Arora2 1ICAR-IARI, Regional Station, Shimla, India 2ICAR-Indian Agricultural Research Institute, New Delhi, India 3ICAR-Indian Agricultural Research Institute, Regional Station, Karnal, India 4ICAR-Indian Agricultural Research Institute, Regional Station, Indore, India 5ICAR-Indian Agricultural Research Institute, Regional Station,Wellington, India 6ICAR-Indian Agricultural Research Institute, Regional Station,Pusa, India 7ICAR-NIBSM, Raipur, India 8ICAR-Indian Institute of Wheat and Barley Research, Karnal, India 9ICAR-Krishi Bhawan, New Delhi

Integrated Disease Management of Root Rot of Papaya in Eastern Gangetic Plains of India

The root rot disease is one of the major problems for papaya cultivation in eastern Gangetic plains of India. Field experiments for two years were conducted during 2013–14 and 2014–15 to evaluate the efficacy of cultural practices, agronomical practices along with chemical fungicides applied as soil drenching either individually or in combinations. The experiment was planned to work out the integrated disease management system against root rot disease in papaya, and simultaneously their role in enhancing the fruit yield and its attributes. The results indicated that organic mulch and soil mounding either singly or in combination reduce the disease incidences along with increase in papaya yield and its attributes. Application of organic mulch + soil mounding with fungicide drenching reveals their posi-tive combined effect on reduction of disease inci-dence and severity levels along with increase in fruit yield and its attributes. Integrated approach-es including organic mulch + soil mounding + soil drenching with metalaxyl + mancozeb re-vealed significantly the highest control of root rot disease (97%) along with the highest increase in fruit yield (36%) and its contributing traits. The highest disease incidence (45%) along with the lowest fruit yield/plant (33.28 kg) and its attrib-uting traits were recorded in control during both the years, 2013–14 and 2014–15. Organic mulch and soil mounding is most effective for disease management in the North Eastern Plains Zone (NEPZ), especially in sandy loam soils. Results of the present study elucidate the combined effect of integrated disease management practices (organic mulch + soil mounding and soil drench-ing with metalaxyl + mancozeb) for root rot man-agement in papaya under eastern Gangetic plains of India.

Effect of crop residue and residual zinc on zinc fractions and their contribution to zinc uptake under rice-wheat cropping system in calciorthents

The long term effect of crop residue and residual zinc on Zn fractions in soil and their contribution to Zn uptake in rice-wheat system was studied in calciorthents of the Rajendra Agricultural University, Pusa, Samastipur (Bihar) during 2010–11 and 2011–12. Application of zinc and crop residue increased the water soluble+exchangeable, complexed, organically bound, carbonate and amorphous oxide, crystalline oxide, residual and total Zn in the soil. The order of dominance of different fractions in soil was total Zn (164.35 mg/kg)> residual-Zn (156.41 mg/kg) >Zn bound to crystalline oxide (3.06 mg/kg)>complexed Zn (2.27 mg/kg)>organically bound Zn (1.14 mg/kg)> water soluble plus exchangeable Zn (0.84 mg/kg) and Zn bound carbonate and amorphous oxide (0.73 mg/kg). All the soil Zn fractions were significantly correlated among themselves indicating existence of a dynamic equilibrium with each other. Zinc uptake by rice-wheat was improved with zinc along with crop residue plus compost. Among different Zn fractions, Zn bound to crystalline oxide, followed by Zn bound to carbonate and amorphous oxide played a key role in explaining the variation in yield and nutrient uptake by rice and wheat. The highest zinc uptake by rice and wheat was reported with the conjoint use of 100% crop residue and 10 kg Zn/ha.

First report of Sclerotinia rot of pigeonpea caused by Sclerotinia sclerotiorum (Lib.) de Bary in India

Abstract Sclerotinia stem rot caused by Sclerotinia sclerotiorum (Lib.) de Bary was observed for the first time on pigeonpea in Pusa, Bihar (India) during the years 2012–2014. Typical symptoms of the disease included blighting of twigs, stem lesions, and development of cottony white mycelium and numerous large sclerotia on diseased plant parts. The fungus was identified on the basis of cultural and morphological characteristics, and its pathogenicity was also established. The internal transcribed spacer (ITS) region of pathogen was amplified with primers ITS1 and ITS4, which revealed 100% query coverage along with 99% identity with S. sclerotiorum recovered from different hosts. The highest disease incidence was recorded on cultivar ‘ICPL151’, whereas cultivars ‘MAL13’ and ‘Kudrat’ were observed to have significantly less disease under natural conditions.