Breeding wheat genotypes for eastern regions of India

Project: Developing high yielding and climate resilient wheat varieties

Sub Project: Breeding wheat genotypes for eastern regions of India

3.2.1

Genesis and rationale of the project: Wheat productivity enhancement through increased yield and resistance is considered as most important thematic area for IGP due to varying climatic conditions that have been experienced.    Wheat crop occupy about 11 million ha area in eastern region and thus number of genotypes are to being developed for commercial cultivation for the regions of that showed better yield potential as well as resistance to diseases like spot blotch and brown rust along with desired quality parameters.  In addition, some area specific problems like pre-harvest sprouting (PHS), salinity, water logging, etc. are also taken as target traits to architect wheat for high yielding and wider adaptability. Efforts are also laid to develop varieties meeting standards of grain quality in appearance as well as in protein content. This wheat improvement programme has focus on above needs and is executed in view following objectives:

  • Development of high yielding genotypes having tolerance to spot blotch, leaf rust and pre-harvest sprouting (PHS).
  • Evaluation of breeding material for major biotic and abiotic stress tolerance and quality traits using physiological, phyto-pathological, biochemical and molecular tools.
  • Sharing shuttle breeding material for multi-location evaluationfor identifying stable genotypes.
  • Anticipatory breeding for tackling wheat blast

Major Achievements of the programme

At institute level, this is one of the long term wheat improvement programme aimed to develop wheat genotypes with high yield, enhanced tolerance and stability across the eastern regions of India. This project is complemented by inputs from other externally funded projects such, DBT-Spot Blotch, NATP (MM), DFID, ACIAR-ICAR collaborative project wheat improvement. Different varieties and genetic stocks were developed for different traits for cultivation by farmers and use in breeding high yielding varieties with specific traits, respectively.

DBW 39: This programme has developed a new variety, DBW 39 for irrigated, timely sown3.2.2 condition of North Eastern Plains Zone (NEPZ), having yield potential of 55.2q/ha thereby meaning that under better management conditions it can give very high yields. Also, it has shown wider adaptability and stable yields under timely as well as late sown conditions at many locations of north eastern India. DBW 39 has a rare combination for chapati, bread and biscuit quality characteristics as evident from high chapati score (7.95) at par with best available variety (C 306), bread quality score (7.08), bread loaf volume (562) and highest biscuit spread factor (7.27). DBW 39 has sizable area under cultivation in West Bengal and its demand is increasing.

DBW 46 (INGR 11010) : Bread wheat (Triticum aestivum L.) genotype DBW 46 was developed out of cross PBW 343/INQ and has yield potential up to 64.5q/ha. In coordinated trials, DBW 46 has shown highest 1000-grain weight under timely sown condition and minimum reduction in the grain weight under late sown situation thereby indicating that it has some degree of heat tolerance. DBW 46 showed high degree of resistance to leaf blight (24 score), good grain appearance, desirable hectolitre weight and sedimentation value. For nutritional attributes, DBW 46 showed very high gluten index (71) and moderate nutritional quality attributes viz; zinc (35.6 ppm), iron (44.2 ppm), copper (5.14 ppm) and manganese (40.1ppm). In view of the above merits, DBW 46 might be utilizing as a donor parent for improving yield, disease resistance, quality and variety of products.

DBW 51 (INGR 11011):  A nutrient dense bread wheat genotype DBW 51 was developed out of cross SITE/MILAN has high protein content (13.51%), high Glu-1 score (10) and has a rare combination for three major end products (chapati, bread and biscuit). It also showed high iron (50.4 ppm), high yellow pigment (4.07), zinc (35.6 ppm), copper (5.50 ppm) and also high content of manganese (45.0 ppm) thereby indicating that this genotype has potential to accumulate more micro-nutrients. It has shown resistance against all the presently virulent pathotypes of yellow (46S 119 & 78S 84) and brown (77-5 & 104-2) rusts, thereby indicating the presence of wide spectrum of genes to protect this genotypes for a longer time. The genotype has the highest tolerance level against leaf blight (23 score). Having desirable combination of traits, DBW 51 will serve as potential donor for breeding future wheat genotypes.

Genetic stocks registered for different traits

Genotype INGR #  Pedigree Special Feature
LBRL-1 INGR 08058 PBW 343 / Chirya 3 Spot blotch resistance
LBRL- 4 INGR 08056 Breedsel 172/ PC-OE-BW 22 Spot blotch resistance
LBRL- 6 INGR 08057 UP262/  Chirya 7 Spot blotch resistance
LBRL-11 INGR 09010 NW 1014/ Chirya 7 Spot blotch resistance
LBRL-13 INGR 09011 Milan / BH 1146 Spot blotch resistance
DBW 46 INGR 11010 PBW 343/INQ 21 Multiple disease resistance
DBW 51 INGR 11011 SITE/MILAN Nutrient dense
LBRIL 102 INGR15060 SONALIKA / BH 1146 Spot blotch resistance
LBRIL 189 INGR16013 Kanchan/Chirya 1 Spot Blotch resistance
DBW 150 INGR 17006 DBW 16/GW 322 Heat stress tolerance

Double digit scale to appraise spot blotch disease: A new double digit scale taking into account the blight severity on upper two leaves was devised and found to be more workable, convenient and time saving, especially when evaluating large breeding populations. The scale was formulated by taking into consideration the two assumptions (i) that the difference of blight severity on two upper leaves never exceeds beyond 20% and  the severity on top leaf (flag leaf) is always lesser than 2nd top leaf. Double-digit value is assigned to the disease severity that established on a genotype and the values have been grouped into various categories of resistant and susceptible response.

 

Severity
(% blighted area)**

Rating
Top (flag) leaf Second top leaf Disease response Range of values
0 0-1 Highly resistant (HR) 00-01
1-2 2-4 Resistant(R) 12-24
3-4 4-6 Moderately resistant (MR) 34-46
5-6 6-8 Moderately susceptible (MS) 56-68
7-8 8-9 Susceptible (S) 78-89
9 9 Highly susceptible (HS) 99

 

Sharing of ISBL lines with researchers in eastern region: Major wheat breeding centres in eastern region viz. Shillongani, Ranchi, Sabour, Faizabad, Patna and Coochbehar were provided with breeding lines in the form of Institute shuttle breeding lines for strengthening their breeding programmes. The researchers can make use of the material for hybridization, selections and come up with advanced breeding lines best suited to their requirements.

QTLs identified for Spot blotch resistance:Three new QTLs namely QSb.iiwbr-7B, QSb.iiwbr-7D in population Sonalika/BH 1146 and QSb.iiwbr-7D in population Kanchan/Chirya 1 have been identified and will be utilized for MAS to improve spot blotch resistance.

This programme has initiated activity to safely maintain the mapping populations developed for different traits under various projects/programmes. About 50 g seed of each line (packed in sealed aluminium envelopes) of 15 mapping populations was deposited for medium term storage under GRU. These populations will only be shared with interested researchers as per the terms specified and the indenter will supply genetically pure seed of each indented line back to IIWBR so as to support rejuvenation process and also ensure credit sharing in all publications, products, IPR etc.

Wheat improvement for water logging, salinity and element toxicities in India: Genotypes have been identified based on geometric mean productivity (GMP), stress tolerance index (STI), mean productivity (MP), harmonic mean (HM) and stress tolerance score (STS) after rigorous evaluation under waterlogging stress conditions. One genotype BH 1146 has been identified as most Al and Mn tolerant indicator genotype. Apart from this, three SSD populations (DBW 17/BH 1146, DBW 16/BH 1146, PBW-550/Chirya-7) were developed and phenotyped across locations. Elite lines were contributed to the national system for further improvement by different breeders through different nurseries. The environmental characterization work has resulted in generating the information for the first time that Al toxicity can be a significant constraint in sodic soils and there are some evidences that Boron toxicity may be a constraint in the ground water in many salt affected areas. Confirmation of these results may provide useful inputs for the breeding methodology for waterlogging tolerance. Knowledge generation with respect to genetics of waterlogging tolerance, breeding methodology, physiological and environmental characterization, refined screening protocols for element toxicities and waterlogging tolerance will help the breeders to develop the waterlogging tolerant materials more effectively.

Results of preliminary screening for pre-harvest sprouting tolerance

 Estimation of Germination index (GI) and Susceptibility index (SI) in 1100 diverse lines for PHS was carried out, and 179 lines were selected that showed tolerance to PHS under controlled conditions. GI of these 179 lines ranged from highly tolerant (GI<0.25) for7 lines; tolerant (0.26 – 0.40) for 10 lines and remaining 162 lines were moderately tolerant (> 0.41).  Confirmatory testing of this trait among the tolerant lines using molecular marker approach will serve as potential tool for screening against PHS tolerance in wheat.

Anticipatory breeding programme for mitigating new threat of Wheat Blast

 In view of the report of wheat blast from Bangladesh during 2016 crop season, ICAR-Indian Institute of Wheat & Barley Research initiated anticipatory breeding programme. For this purpose, a special trial/nursery consisting of 50 genotypes was planted at six locations along the borders of Bangladesh. The trial planted near Lalgola (Murshidabad) showed incidence of wheat blast like symptoms (ranging between 7- 60%) except variety DBW 189 which was completely free from any disease. The variable reaction of genotypes is encouraging but these results need further evaluation for confirmation. Besides, targeted crosses have been attempted with the available potential donors (BH 1146, Milan, SHA7, Ae. tauschi (derivatives), varieties possessing / carrying Lr 34 etc., genotypes possessing 2NS translocation) with agronomically superior varieties of NEPZ

Creating repository of mapping populations of wheat at GRU

This programme has initiated activity to safely maintain the mapping populations developed for different traits under various projects/programmes. About 50 g seed of each line (packed in sealed aluminium envelopes) of 15 mapping populations was deposited for medium term storage under GRU. These populations will only be shared with interested researchers as per the terms specified and the indenter will supply genetically pure seed of each indented line back to IIWBR so as to support rejuvenation process and also ensure credit sharing in all publications, products, IPR etc.