HIMACHAL PRADESH KRISHI VISHVAVIDYALAYA

Department of Plant Breeding and Genetics, Palampur - 176 062 (H.P.), India.

The current status and some achievements of the wheat breeding program.

G.S. Sethi, Satish C. Sharma, K.S. Thakur, D.L. Sharma, Ashwani Kumar, S.C. Negi, and S.L. Garton.

Wheat is the most important good grain crop of Himachal Pradesh, occupying an area of approximately 370,000 hectares, with a total grain production of about 600,000 tons. However, the average productivity (15-16 q/ha) of wheat is far below the national average of 25-26 q/ha. The low productivity in the state is caused by many factors: rainfed cultivation accounts for 82 % of the area planted; less area is planted with improved and recommended wheat cultivars; stripe and leaf rusts, hill and Karnal bunts, powdery mildew, and loose smut are prevalent; many farmers sow seed by broadcast methods; an imbalance exists in the use of fertilizers; and weeds are prevalent in the fields. Our research efforts have focused on developing high-yielding, disease-resistant, drought-tolerant, and widely adaptable wheat cultivars for the different production conditions in the state.

Identification of elite wheat cultivars. A total of 57 wheat cultivars were evaluated in Station trials under different production conditions (early, timely, and late sowing and rainfed and irrigated) over several locations in the Himachal Pradesh. Based on high grain yield, resistance to different diseases, and agronomic superiority, only 14 wheat cultivars were finally selected and inducted into the Coordinated Trials for the Northern Hill Zone during 1995-96 under different production conditions. Two wheat cultivars, HPW 114 and HPW 125, were promoted into the Advance Varietal testing under timely sown, rainfed and irrigated conditions. Of these two, HPW 114 is in the final year of testing. The performance of this cultivar in the Northern Hill Zone for the last 2 years is presented in Table 1.

Table 1. Performance of cultivar HPW 114 under timely sown, rainfed and irrigated conditions in the

cropping years 1993-94 and 1994-95, compared with the check cultivars HS 240 and HD 2380.

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Mean grain yield q/ha Rust reaction*

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Overall

Cultivar 1993-94 1994-95 mean Yellow Brown

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Timely sown, rainfed

HPW 114 28.4 29.0 28.7 0 0

HS 240 28.6 25.8 27.2 0 0

HD 2380 24.4 26.5 25.4 ó 100S (80.0)

Irrigated

HPW 114 36.4 37.1 36.7 0 2S (0.7)

HS 240 35.8 39.0 37.4 0 5MR (0.7)

HD 2380 35.6 39.1 37.3 60S (27.3) 100S (53.3)

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*Natural infection.

The newly developed wheat cultivar HPW 114 has shown resistance to rusts and is statistically equal to the highest yielding check cultivar HS 240 in grain yield.

`On-farm' trials. On farm trials of the newly developed wheat cultivar HPW 89, in comparison to the existing recommended cultivar HS 240, were made in different districts and at the university research stations of the state under timely sown, rainfed and irrigated production. Table 2 summarized the results of the 1994-95 cropping season.

Table 2. Comparison of mean grain yields (q/ha) of the HPW 89 and HS 240 cultivars under different production conditions.

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Timely sown, rainfed Timely sown, irrigated

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Zone HPW 89 HS 240 HPW 89 HS 240

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I 26.58 (3) 22.67 (3) 31.31 (4) 30.31 (4)

II 32.81 (5) 26.92 (5) 35.50 (12) 34.34 (12)

Mean (weighted) 30.47 (8) 25.32 (8) 34.45 (16) 33.33 (16)

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* Figures in parentheses indicate the number of trials for the given mean.

HPW 89 exhibited a high degree of resistance to both yellow and brown rusts and has shown higher tolerance to Karnal bunt (5.71 %) compared to HS 240 (11.5 %), HD 2380 (20.0 %), and Sonalika (12.0 %). HPW 89 also was immune to head scab (0) compared to HS 240 (11 %), HD 2380 (32 %), and Sonalika (11 %). HPW 89 is earlier in flowering and maturity and has larger grains than HS 240.

Hybridization, shuttling, and selection of wheat breeding material. One hundred thirty single crosses were made involving proven sources of resistance to strip and leaf rusts (CPAN 3031, CPAN 4095, CPAN 4096, CPAN 4078, CPAN 4076, CPAN 4073, CPAN 4039, CPAN 3074, CPAN 3067, 2-HWESN-203, CPAN 4103, CPAN 4117, CPAN 4140, CPAN 4139, CPAN 4138, CPAN 4137, CPAN 4136, CPAN 4123, CPAN 4141, Menyo, PBW 65, and N18859) and cultivars with superior agronomic bases (HS 240, HPW 42, HS 2380, HS 277, VL 616, HS 295, HS 2285, HPW 89, and HPW 114). The wheat breeding material generated over the years were shuttled, evaluated, and selected on the basis of resistance to yellow and brown rusts, plant type, and maturity at different locations during the winter of 1994-95 at Bajaura (elev. 1,098 m), Dhaulakuan (elev. 456 m), Kukumseri (elev. 2,300 m), and Palampur and Malan (elev. 1,300 m). These locations are hot-spots for yellow rust, brown rust, and powdery mildew infection. The material evaluated and selected during 1994-95 is listed in Table 3.

Table 3. Wheat breeding material selected during 1994-95.

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Generation Location Evaluated Selected

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F2-F3 Bajaura/Kukumseri 171 populations 290 progenies

F4-F5 Dhaulakuan/Kukumseri 137 progenies 145 single plants

F6-F8 Malan/Palampur 153 progenies 115 progenies

148 bulks 60 bulks

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High degrees of natural infection of strip and leaf rusts and powdery mildew were recorded at the above-mentioned locations.

The `winter x spring' hybridization program. We evaluated 900 stocks of T. aestivum and T. durum and triticale at the research station in Malan for yellow and brown rust and powdery mildew. The material consisted of NGSN, EIGSN, AVT-II year, and microtrial entries and selections from CIMMYT. In all, about 200 entries were found to be resistant to all the diseases.

Virulence analysis of E. graminis f. sp. tritici. The virulence pattern of conidial (41) and ascospore (34) isolates of E. graminis tritici collected from the districts of Kangra, Chamba, Mandi, Iahaul, Spiti, and Sirmour were elucidated. The isolates were inoculated on differential lines with single powdery mildew-resistance genes Pm1 through Pm8, Pm(Ma), Pm(Md), W150, W176, and a line with a combination of genes Pm2 + Pm4b, Pm4b + Pm8, and Pm2 + Pm6. On the basis of the differential reaction, the conidial and ascosporic isolates were grouped into 22 and 18 pathotypes, respectively. Pathotype III, in conidial and ascosporic isolates, which had virulence on genes Pm2 (CI12632/Ce8), Pm3a, Pm3c, Pm3e, Pm5, Pm6, Pm7, Pm8, and Pm ef, was the most prevalent. Pathotype VIII with virulence on genes Pm3c, Pm3f, Pm5, Pm6, Pm8, Pm3c, Pm3f and Pm3c, and Pm7 and Pm8, was the least virulent. The isolates with virulence on genes Pm3a, Pm3c, Pm3e, Pm5, Pm6, Pm7, Pm8, Pmf, Pm(Ma) were the most prevalent. Virulence for genes Pm1, Pm2, Pm3b, Pm4a, Pm4b, Pm(Ma), Pm2 + Pm6, Pm2 + Pm4a, and Pm4b + Pm8 was rare.

The genetics of stripe rust resistance and its utilization in wheat breeding programs. An ICAR-funded ad hoc project was completed in 1995 at Fajaura. The salient results and progress are:

1. Multiple culture tests with the most virulent stripe rust races (P, T, K, and N) were used to classify 315 wheats into 15 diverse groups at the seedling stage.

2. Inheritance studies at the seedling stage to race P revealed the presence of one recessive gene in the cultivars Bobwhite; CPAN 1990, 2016, 2055, 3004, 3031, 3050, and 3071; HD 2380; HS 295 and 316; K 8387; and Veery `S'; one dominant gene in HPW 62, CPAN 3078, and HI 1114; one dominant and one recessive (independent) gene in CPAN 3057, 3067, 3077, and VL 703; two independent recessive genes in CPAN 2051, 2063, 3072, and 3074; and two dominant complementary and one recessive gene in CPAN 4066.

3. Allelic relationships were investigated among 10 resistant stocks: Bobwhite; CPAN 2051, 2055, 3031, 3067, and 3071; HPW 42 and 62; HD 2380; and HS 295.

4. Adult plant resistance to specific races was observed in Bounty, CPAN 1796, Cocoroque 75, Mantana, Millewa, Mukta, Oxlay, Pavon 76, RL 6070, TD-13, Surproza, Tonichi, UP 1109, and WL 410.

5. Partial resistance was observed in Egret 1 and HP 1209.

6. TD-13 has one dominant gene for adult plant resistance, whereas Frontana has one recessive APR gene. Raj 1972 and Raj 1973 have diverse, but additive, APR genes.

7. Transfer of resistance was initiated, and the material has reached the F5 generation.

Wheat front-line demonstration. Five front-line demonstrations of released and recommended cultivars were conducted at different sites in the Kangra district. The demonstrations covered an area of 20 ha and involved four cultivars, VL 616 (early sown), HD 2380 and HS 240 (timely sown), and HS 295 (late planted). Grain yield increases for 24-60 % of these cultivars over local varieties from the farmers' fields were observed.