21.12.2013 Views

ICRISAT Archival Report 2006 - The seedlings of success in the ...

ICRISAT Archival Report 2006 - The seedlings of success in the ...

ICRISAT Archival Report 2006 - The seedlings of success in the ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Milestone 5A.1.1.2: Five male-sterile l<strong>in</strong>es resistant each to gra<strong>in</strong> mold and shoot fly developed<br />

(BVSR/RPT/HCS/RS, 2008)<br />

Gra<strong>in</strong> mold resistance: Gra<strong>in</strong> mold is one <strong>of</strong> <strong>the</strong> major biotic constra<strong>in</strong>ts <strong>in</strong> gra<strong>in</strong> sorghum dur<strong>in</strong>g <strong>the</strong> ra<strong>in</strong>y season.<br />

Efforts have been underway to develop new hybrid seed parents for gra<strong>in</strong> mold resistance (GMR) as <strong>the</strong> available<br />

hybrid seed parents only possess moderate resistance levels.<br />

1. A total <strong>of</strong> 26 F 6 progenies developed from <strong>the</strong> crosses <strong>in</strong>volv<strong>in</strong>g gra<strong>in</strong> mold resistant B-l<strong>in</strong>es, gra<strong>in</strong> mold<br />

resistant landraces and high-yield<strong>in</strong>g B-l<strong>in</strong>es were evaluated <strong>in</strong> a prelim<strong>in</strong>ary screen<strong>in</strong>g trial for GMR and also<br />

testcrossed to identify ma<strong>in</strong>ta<strong>in</strong>er l<strong>in</strong>es for conversion <strong>in</strong>to male-sterile l<strong>in</strong>es dur<strong>in</strong>g <strong>the</strong> <strong>2006</strong> ra<strong>in</strong>y season. <strong>The</strong><br />

data from <strong>the</strong> screen<strong>in</strong>g nursery is awaited. From <strong>the</strong> breed<strong>in</strong>g nursery, 35 F 7 s tolerant to gra<strong>in</strong> mold (PGMR<br />

≤5) and <strong>the</strong> desirable agronomic traits were produced and harvested along with <strong>the</strong>ir testcrosses for assess<strong>in</strong>g<br />

<strong>the</strong>ir ma<strong>in</strong>ta<strong>in</strong>er/restorer reaction<br />

2. In an advanced screen<strong>in</strong>g trial for GMR, a total <strong>of</strong> 72 F 6 progenies developed from <strong>the</strong> crosses <strong>of</strong> gra<strong>in</strong> mold<br />

resistant landraces, high-yield<strong>in</strong>g B-l<strong>in</strong>es and gra<strong>in</strong> mold resistant breed<strong>in</strong>g l<strong>in</strong>es were evaluated dur<strong>in</strong>g <strong>the</strong><br />

<strong>2006</strong> ra<strong>in</strong>y season. <strong>The</strong>se progenies along with <strong>the</strong>ir testcrosses on known sources <strong>of</strong> A 1 and A 2 CMS systemsbased<br />

male-sterile l<strong>in</strong>es were also evaluated <strong>in</strong> a separate nursery <strong>in</strong> <strong>the</strong> breed<strong>in</strong>g block dur<strong>in</strong>g <strong>the</strong> <strong>2006</strong> ra<strong>in</strong>y<br />

season. <strong>The</strong> results from screen<strong>in</strong>g trial are awaited. A total <strong>of</strong> n<strong>in</strong>e l<strong>in</strong>es with GMR (PGMR ≤5) and ma<strong>in</strong>ta<strong>in</strong>er<br />

reaction were selected from <strong>the</strong> breed<strong>in</strong>g block nursery. <strong>The</strong>y <strong>in</strong>cluded two white gra<strong>in</strong> l<strong>in</strong>es and seven red gra<strong>in</strong><br />

l<strong>in</strong>es.<br />

Shoot fly resistance: Shoot fly is one <strong>of</strong> <strong>the</strong> major biotic constra<strong>in</strong>ts <strong>in</strong> both ra<strong>in</strong>y and postra<strong>in</strong>y seasons.<br />

Consider<strong>in</strong>g that <strong>the</strong> available seed parents bred for shoot fly resistance (SFR) possess only moderate resistance<br />

levels and gra<strong>in</strong> yield potential, efforts are underway to develop and diversify seed parents for SFR.<br />

1. A total <strong>of</strong> 110 ra<strong>in</strong>y season-adapted F 7 progenies (which <strong>in</strong>cluded 55 progenies with testcrosses and <strong>the</strong><br />

rema<strong>in</strong><strong>in</strong>g 55 yet to be testcrossed) derived from crosses <strong>in</strong>volv<strong>in</strong>g shoot fly resistant B-l<strong>in</strong>es and high-yield<strong>in</strong>g<br />

B-l<strong>in</strong>es were advanced with selection <strong>in</strong> 2005 postra<strong>in</strong>y season. Based on ma<strong>in</strong>ta<strong>in</strong>er/restorer reaction, 36<br />

testcrosses and parents were selected for backcross<strong>in</strong>g. However, backcross<strong>in</strong>g could be carried out only on 32<br />

parents (BC 1 s). <strong>The</strong> rema<strong>in</strong><strong>in</strong>g four testcrosses and parents will be advanced and testcrossed along with <strong>the</strong><br />

evaluation and cont<strong>in</strong>uation <strong>of</strong> backcross<strong>in</strong>g <strong>of</strong> 32 BC 1 s (as set 1) <strong>in</strong> <strong>the</strong> <strong>2006</strong> ra<strong>in</strong>y season. <strong>The</strong> 55 F 7 progenies<br />

(which were yet to be testcrossed) were testcrossed onto known A 1 and A 2 CMS systems-based male-sterile<br />

l<strong>in</strong>es <strong>in</strong> 2005 postra<strong>in</strong>y season. Based on visual assessment <strong>of</strong> agronomic aspects, 39 testcrosses and parents<br />

were selected for assess<strong>in</strong>g <strong>the</strong>ir ma<strong>in</strong>ta<strong>in</strong>er/restorer reaction (as set 2) <strong>in</strong> <strong>the</strong> <strong>2006</strong> ra<strong>in</strong>y season.<br />

• <strong>The</strong> set 1 (32 BC 1 s and 4 testcrosses parents) and set 2 (39 testcrosses parents) were screened for SFR <strong>in</strong><br />

a screen<strong>in</strong>g block and also evaluated <strong>in</strong> a breed<strong>in</strong>g block for a conversion program <strong>in</strong> <strong>the</strong> <strong>2006</strong> ra<strong>in</strong>y<br />

season. In set 1, <strong>the</strong> deadhearts ranged from 40 to 69%. <strong>The</strong> resistant control (IS 18551) had 59%<br />

deadhearts and susceptible control (296 B) had 80% deadhearts. Correspond<strong>in</strong>g BC 1 s <strong>in</strong> breed<strong>in</strong>g block<br />

which showed below 60% deadhearts <strong>in</strong> screen<strong>in</strong>g block were fur<strong>the</strong>r backcrossed and a total <strong>of</strong> 20 BC 2 s<br />

(8 on A 1 , 8 on A 2 and 4 A 1 and A 2 ) were selected.<br />

• In set 2, 35 testcrosses and parents and four parents to be testcrossed were screened for SFR <strong>in</strong> screen<strong>in</strong>g<br />

block and also evaluated <strong>in</strong> breed<strong>in</strong>g block for conversion program <strong>in</strong> <strong>the</strong> <strong>2006</strong> ra<strong>in</strong>y season. Due to very<br />

poor germ<strong>in</strong>ation and crop establishment, data on deadhearts could not be recorded <strong>in</strong> <strong>the</strong> screen<strong>in</strong>g<br />

block. However, <strong>in</strong> <strong>the</strong> breed<strong>in</strong>g block, based on agronomic performance, 10 testcross progenies with<br />

ma<strong>in</strong>ta<strong>in</strong>er reaction (BC 1 s) (6 on A 1 and 4 on A 1 and A 2 ) were selected for screen<strong>in</strong>g for shoot fly<br />

resistance.<br />

BVS Reddy, RPThakur and HCSharma<br />

Advanced B-l<strong>in</strong>es resistant to sorghum shoot fly: In an advanced B-l<strong>in</strong>e trial, 21 l<strong>in</strong>es along with three checks<br />

viz., 296B, ICSB 52, and IS 14384 were evaluated for resistance to shoot fly, A<strong>the</strong>rigona soccata, dur<strong>in</strong>g <strong>the</strong> <strong>2006</strong><br />

postra<strong>in</strong>y season <strong>in</strong> a randomized complete block design with three replications. Data were recorded on leaf<br />

gloss<strong>in</strong>ess score (1 = highly glossy, and 5 = non-glossy) and shoot fly deadhearts at 14 and 18 days after seedl<strong>in</strong>g<br />

emergence. <strong>The</strong> leaf glossy score ranged from 4.7 to 5.0 <strong>in</strong> <strong>the</strong> advanced B-l<strong>in</strong>es compared to 5.0 <strong>in</strong> 296B and 2.7 <strong>in</strong><br />

127

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!