High Yielding NERICA Mutant Rice for Upland Areas and Hope for Bangladeshi Farmers ID: 154 Mirza Mofazzal Islam, PhD Chief Scientific Officer and Head Plant Breeding Division Bangladesh Institute of Nuclear Agriculture BAU Campus, Mymensingh-2202 Bangladesh Email : mirza_islam@yahoo.com Paper presented at the FAO/IAEA International Symposium on International Plant Mutation Breeding and Biotechnology, 27-31 August 2018, Vienna, Austria

Causes of Drought Deficiency Human Causes Drying out of Surface Rainfall or Precipitation Deficiency Human Causes Drying out of Surface Water Flow Global Warming

Effects of Drought Droughts Reduced Crop yields Environmental Impacts of Droughts Reduced Crop yields Drying out of water bodies Reduction in soil quality Unsuitable conditions for plant and vegetation survival Migration and even death of People, Animals and Wildlife

Bangladesh is a developing country and the main staple food is rice Bangladesh is a developing country and the main staple food is rice. Without rice no meal is considered for the people of this country. The total land area of Bangladesh is 1,47,570 sq km and the total cultivable land is 85.05 million ha (BBS, 2016). Now the days, the population of Bangladesh increasing and the land are decreasing. So, Bangladesh need to produce more rice with this limited cultivable land. There are many approaches to develop rice variety. Mutation breeding is one of them.

In Bangladesh, the yield of Aus (upland) (Mid March- June) varieties is very low (1.5-2.0) tha-1 due to limited water supply. The Aus (upland) season is the water deficit season in Bangladesh. A strong drought can cause greater than 40% damage to broadcast Aus (upland) rice. During the month of July-September, it also causes significant destruction to the T. Aman (rainfed) crop in approximately 2.32 million ha every year. In the rabi season, about 1.2 million ha of agricultural land face droughts of different magnitudes.

NERICA (New Rice for Africa) are the varieties which are developed by African Rice Center. NERICA was originated from progeny of O. sativa  O. glaberrima. NERICA is upland rice grown in drought condition, growth duration ranges from 110-125 days. Adaptability of NERICA lines were tested for last several years, but these varieties are not adapted or accepted in Bangladesh. This was a big challenge to overcome such defects or barriers in NERICA. Therefore, with this view the induced mutation was initiated to develop early, drought tolerant and high yielding rice variety(s).

Materials and Methods Given radiation: 250, 300, 350 Gy Irradiated seed sample: 2000 seeds/each variety/each doses Irradiation of 3 varieties (NERICA-1, NERICA-4 and NERICA-10) Growing of M1 plants (2,000 Nos.) Growing of M2 population (10,000 Nos.) Phenotypic selection of M2 plants (556 Nos.) Growing of M3 population (556 Nos.) Selection of M4 Generation (37 Nos.) Selection of M5 Generation (6 Nos.) Follow Yield Trials/Multi-location trials Released as Variety  

RESULTS Performance of two NERICA-1, one NERICA-4 and one NERICA-10 mutants Table 1. Mean values of parents and selected mutants for various plant parameters at M6 generation Mutant Days to maturity Plant height (cm) Effective tillers (no.) Panicle length (cm) Filled grains/ panicle Unfilled grains/panicle (no) 1000 seed wt. (g) Grain yield (t/ha) N1/250/P-6-2-6-1 108 102 13 25.6 180 27 23.8 5.1 N1/250/P-7-3-12-2-1 112 120 10 33.9 145 35 22.9 4.6 N4/250/P-1(2) 111 107 24.5 195 25 22.6 5.8 N4/350/P-4(5) 113 106 12 24.4 212 16 25.4 6.2 N4/250/P-2(6)-26 104 14 24.2 26 22.2 5.7 N10/350/P-5-4 91 125 23.3 4.5 NERICA-1(Parent) 121 7 49 26.9 2.9 NERICA-4(Parent) 118 99 105 37 28.1 3.9 NERICA-10(Parent) 123 98 23.5 28.0 3.2 Note: N1= NERICA-1, N4 = NERICA-4 and N10 = NERICA-10 (all are designated as mutant)

Field evaluation of a drought tolerant N4/350/P-4(5) mutant Table 2. Morphological, agronomical, grain characters of the drought tolerant NERICA-4 mutant (N4/350/P-4(5)) during Aus (upland) season, 2016 Mutant/variety Plant height (cm) Days to maturity No. of effective tillers/hill No. of filled grains/panicle 1000 grain wt. (g) N4/350/P-4(5) 106 100 12 108 24.0 BRRI dhan48 (check)* 103 104 10 93 25.0 *Popular variety

Table 3. Yield performance of the NERICA-4 mutant (N4/350/P-4(5)) at multi-location trials grown in Aus (upland) season 2016 Mutant/variety Grain yield (tha-1) Mean L1 L2 L3 L4 L5 N4/350/P-4(5) 6.11 4.73 6.22 3.94 3.95 4.99 BRRI dhan48 (check) 5.74 3.90 5.83 3.43 3.49 4.48 L1- Magura, L2- Mymensingh, L3- Khagrachari , L4- Godagari (Rajshahi ) and L5- Nokla (Sherpur)

Table 4. Grain characteristics of the NERICA-4 mutant Mutant/variety Milling Yield (%) Head rice yield(%) Chalkinessa Whole grain length (mm) Dehulled grainkernel-1 Amylose (%) Length (mm) Breadth (mm) LB-1 ratio Size and shape N4/350/P-4(5) 72 93 wb1 8.1 6.2 3.0 2.06 Medium medium 23.5 BRRI dhan48 (check) 71 90 8.2 6.3 2.9 2.17 24.0 *Wb1 = Less than 10% chalkiness

Field evaluation of a drought tolerant N10/350/P-5-4mutant in Aus (upland) season Table 5. Yield and yield contributing characters of the proposed drought tolerant mutant rice and check variety grown in Aus (upland) season 2016-17 Mutant/variety Plant height (cm) Days to maturity No. of filled grains/panicle No. of effective tillers/hill 1000 grain wt. (g) N10/350/P-5-4 98 105 140 15 23.5 BR26 (check)* 110 127 11 21.5 *Popular variety

Table 6. Yield performances of the NERICA- mutant at multi-location trials grown in Aus (upland) season 2017 Designation Grain yield (t/ha) Mean yield (t/ha) L1 L2 L3 L4 L5 N10/350/P-5-4 4.48 4.73 4.92 3.95 3.80 4.40 BR26 (check) 3.86 4.56 4.82 3.70 3.60 4.10 L1- Fulbaria (Mymensingh), L2- BINA sub-station, Nalitabari, L3- BINA sub-station, Magura, L4-Tanore (Rajshahi) and L5- Khagrachari.

Table 7. Grain characteristics of the proposed variety mutant with std. checks Milling yield (%) Head rice yield (%) Chalkinessa Whole grain length (mm) Dehulled grain/kernel Amylose content (%) Length (mm) Breadth (mm) L/B ratio Size and shape N10/350/P-5-4 74 93 wb1 9.3 7.2 2.0 3.6 Long slender 25.1 BR26 (check) 71 91 9.1 7.0 3.5 22.7 a Wb1 = Less than 10% chalkiness

CONCLUSION African rice NERICA cultivar have some problem viz. un-uniform flowering, late in maturity and low yielding in Bangladesh condition. With this view we initiated induced mutation to overcome these defects of NERICA rice at BINA. Two mutants (viz.N4/350/P-4(5) and N10/350/P-5-4 ) out of six promising mutants have been identified for uniform flowering, early maturity (100-105 days) , higher yield (4.5-5.0 t/ha) and well adapted in Bangladesh condition. These two mutants will be released for commercial cultivation in Bangladesh.

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