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AN APPRAISAL OF RESISTANCE OF OLD AND NEW WHEAT GENOTYPES TO

RED FLOUR BEETLE, TRIBIOLIUM CASTANEUM (HERBST).

MUHAMMAD SIDDIQUE KHANZADA

DEPARTMENT OF ENTOMOLOGY

FACULTY OF CROP PROTECTION

SINDH AGRICULTURE UNIVERSITY, TANDO JAM

PAKISTAN

Wheat, Triticum aestivum L. is the important cereal crop and staple food of people of Pakistan.

It occupies the first position in area amongst the cereal crops and covers about 65% of food crop area of the country Wheat was grown on an area of 8.6 million hectares in the year 2008-09 with production target of 25 million tons .

Live adult insects were present in about 75% of the samples taken; the most common species were Sitotroga cerealella (Olivier), Tribolium castaneum (Herbst), Rhizopertha dominica (Fabricius). and Sitophilus spp (Linnaeus) T. castaneum has been found one of major insect species in surveys Tribolium spp. in the food grains give pungent smell and infested flour becomes dirty yellow in colour.

LIFE CYCLE

MODE OF DAMAGE

The damage caused by insect pests to wheat grain has been estimated at 10 to 20% Red flour beetle, Tribolium castaneum (Herbst) is one of the major insect pests of stored grains with cosmopolitan distribution.

The research on the relative resistance of old and modern genotypes of wheat to red flour beetle, Tribolium castaneum (Herbst) was conducted in the laboratory, Department of Entomology, Sindh Agriculture University, Tandojam.. Seeds of wheat varieties were obtained from the Plant Genetics Division, Nuclear Institute of Agriculture, Tandojam.Grains of genotypes were made dust and straw free, and then the sound and healthy grains were selected. The experiment was conducted in the laboratory at 29+2 o C and 65+5% R.H.,, replicated three times in completely randomized block design (CRBD) .The standard samples of each variety used in the experiment were 1000 grains, kept in plastic jars (15x 6 cm). Ten pairs of newly emerged adult red flour beetle, T. castaneum, (both sexes in equivalent numbers) of uniform age structure from laboratory-stock culture were released in each jar. The mouth of each jar was covered with muslin cloth, tightened with rubber band. The observations were taken at 15 days intervals and adult beetle population fluctuations were recorded at each interval by counting the number of adults. Increase/ decrease in adult numbers was considered criterion for the relative resistance of a genotype to insect attack.

MATERIAL METHODS

The following parameters were studied to judge the relative susceptibility of wheat genotypes: a) Adult population b) Percentage grain damage. c) Frass weight and d) percent germination

Each sample was passed through a 60-mesh sieve for separation of frass and grains. The grains containing holes were separated from the sound grains as damaged grains. The percent damage was calculated according to the method of the effect of T. castaneum infestation on germination of seeds was determined after completion of resistance studies. The seeds of all genotypes were divided into three categories i.e., control seeds, healthy seeds and infested seeds from different treatments. Germination of seeds was tested in Petri dishes lined with moist (filter paper). Three replications were kept for every category of seeds of each genotype and there were 25 seeds per treatment. After the compellation of germination, the germination will be checked .The germination of treated (healthy) grains was germinated 100% and treated (damage) grains were not germinated 0%. In control grains 100% germination results.

The data obtained were statistically analyzed by using ANOVA and DMR test by computer programme. The coefficient of correlation between various parameters was also determined.

RESULTTABLE-1. SEED CHARACTERISTICS OF DIFFERENT GENOTYPES OF WHEAT.

S.No NAME OF GENOTYPES WEIGHT OF 1000 GRAINS IN (g)1 T1 Triticum durum 28.33 + 0.33 pqr2 T2 Triticum durum 28.00 + 0.57 qr3 T3 Triticum durum 30.00 + 0.57 lmnopq4 T4 Triticum sphaerococcum 31.67 + 1.33 jklmn5 T5 Triticum sphaerococcum 28.67 + 0.33 opqrr6 T6 Triticum sphaerococcum 30.33+0.88 klmnopq7 T7 Triticum sphaerococcum 31.00 + 0.57 klmnop8 T8 Triticum sphaerococcum 35.67 + 0.33 ghi9 T9 Triticum aestivum 31.33+1.202 jklmno10 T10 Triticum aestivum 34.00 + 1.00 hij11 T11 Triticum aestivum 41.33 + 1.20 cd12 T12 Triticum aestivum 36.33+ 0.66 gh13 T13 Triticum aestivum 33.00 +.57 ijk14 T14 Triticum aestivum 26.00 +1.15 r15 T15 Triticum aestivum 37.67 +1.76 fg16 T16 Triticum aestivum 39.67 + 0.88 def17 T17 Triticum aestivum 38.33 + 0.88 efg18 T18 Triticum aestivum 29.00 + 0.57 nopq19 T19 Triticum aestivum 29.67+ 0.33 mnopq20 T20 Triticum aestivum 37.67+ 1.333 fg21 T21 Triticum aestivum 29.33 + 0.33 mnopq22 T22 Triticum aestivum 32.33 + 1.20 jkl23 T23 Triticum aestivum 44.67 + 0.33 b24 T24 Triticum aestivum 32.00 + 0.57 jklm25 T25 Triticum aestivum 33.00 + 1.15 ijk26 Barani-70 40.33+ 0.33 def27 Bhattai 40.67+ 0.66 de28 Marvi-2000 51.67+1.20 a29 Mehran-89 43.67 + 2.33 bc30 T.J-83 45.33+ 1.45 b

LSD 2.76

TABLE-2. Tribolium castaneum POPULATION AND DAMAGE CHARACTERISTICS ON DIFFERENT GENOTYPES OF WHEAT.

S.NO NAME OF GENOTYPES NO. OF DAMAGED GRAINS

ADULT POPULATION (%) INFESTATION FRASS WEIGHT (mg)

1 T1 Triticum durum 43.67 + 3.18 mno 13.00 + 0.57 cd 4.37 + 0.31 no 36.67 + 0.88 ghijklmn

2 T2 Triticum durum 38.67 + 0.88 opq 6.00 + 1.52 d 3.87 + 0.08 op 29.00 + 4.72 jklmn

3 T3 Triticum durum 40.33 + 4.70 nop 16.33 + 4.09 cd 4.03 + 0.47 o 49.33 + 7.62 defghijkl

4 T4 Triticum sphaerococcum 66.00 + 1.15 hij 14.67 + 2.66 cd 6.60 + 0.11 ij 41.67 + 7.26 efghijklmn

5 T5 Triticum sphaerococcum 93.33 + 5.66 f 25.67 + 4.37 cd 9.33 + 0.56 f 71.67 + 2.72 de

6 T6 Triticum sphaerococcum 77.67 + 5.36 gh 30.00 + 6.24 cd 7.76 + 0.53 gh 59.33 + 9.35 defghijk

7 T7 Triticum sphaerococcum 87.33 + 1.20 fg 41.67 + 12..03 c 8.73 + 0.13 fg 104.33 + 3.38 bc

8 T8 Triticum sphaerococcum 58.33 + 8.41 jkl 14.13 + 3.18 cd 5.83 + 0.84 jkl 61.33 + 35.83 defghi

9 T9 Triticum aestivum 47.33 + 0.66 lmno 10.67 + 2.90 cd 4.73 + 0.06 mno 32.00 + 3.46 hijklmn

10 T10 Triticum aestivum 124.00 + 8.54 d 24.33 + 4.41 cd 12.40 + 0.49 d 60.67 + 5.60 defghij

11 T11 Triticum aestivum 42.33 + 0.66 mno 11.33 + 1.45 cd 4.23 + 0.06 no 30.00 + 13.29 jklm

12 T12 Triticum aestivum 49.00 + 2.08 klmno 13.33 + 4.91 cd 4.90 + 0.20 lmno 30.67 + 2.72 ijklmn

13 T13 Triticum aestivum 20.00 + 3.05 rs 8.33 + 5.36 d 2.00 + 0.30 qrs 18.00 + 7.00 mn

14 T14 Triticum aestivum 29.00 + 5.03 pqr 4.67 + 1.76 d 2.90 + 0.50 pq 19.67 + 2.96 lmn

15 T15 Triticum aestivum 41.00 + 3.21 nop 12.33 + 2.72 cd 4.10 + 0.32 o 35.33 + 8.87 ghijklmn

16 T16 Triticum aestivum 138.67 + 3.33 c 95.00 + 30.07 b 13.87 + 0.33 c 132.67 + 14.51 b

17 T17 Triticum aestivum 164.67 + 2.60 b 27.33 + 7.35 cd 16.47 + 0.26 b 130.67 + 21.82 b

18 T18 Triticum aestivum 116.00 + 2.30 de 18.67 + 2.72 cd 11.60 + 0.23 de 63.67 + 4.91 defg

19 T19 Triticum aestivum 40.67 + 1.33 nop 4.67 + 1.33 d 4.07 + 0.13 o 34.33 + 18.52 hijklm

20 T20 Triticum aestivum 52.00 + 9.16 klmn 10.67 + 0.33 cd 5.20 + 0.52 klmn 38.33 + 6.33 fghijklm

21 T21 Triticum aestivum 284.00 + 27.31 a 132.33 + 48.21 a 28.40 + 0.45 a 228.00 + 22.053 a22 T22 Triticum aestivum 61.67 + 1.33 ijk 15.67 + 3.66 cd 6.17 + 0.13 ijk 47.33 + 8.87 efghijklm

23 T23 Triticum aestivum 109.33 + 1.45 e 25.33 + 4.84 cd 10.93 + 0.14 e 116.33 + 4.84 b

24 T24 Triticum aestivum 26.33 + 2.66 qrs 7.00 + 1.00 d 2.63 + 0.26 qr 25.00 + 4.04 klmn

25 T25 Triticum aestivum 44.33 + 3.71 mno 13.00 + 6.08 cd 4.43 + 0.37 mno 47.67 + 6.48 efghijklm

26 Barani-70 16.33 + 1.45 rs 1.33 + 0.33 c 1.63 + 0.14 rs 14.00 + 2.08 m

27 Bhattai 15.00 + 1.00 s 2.33 + 0.66 d 1.50 + 0.10 s 10.67 + 2.88 n28 Marvi-2000 72.00 + 4.16 hi 26.67 + 0.88 cd 7.20 + 0.41 hi 67.33 + 2.33 def

29 Mehran-89 175.67 + 3.84 b 28.00 + 5.85 cd 16.57 + 0.84 b 80.33 + 6.33 cd

30 T.J-83 54.67 + 3.33 jklm 15.00 + 2.51 cd 5.47 + 0.33 klm 37.33 + 5.03 fghijklmn

LSD 13.01 31.01 1.08 31.67

A correlation study carried out between T. castaneum adult population and different damage parameters, indicated that there was highly significant

(P<0.01), positive correlation between adult population and damaged grains, % infestation and frass production (Fig.1-4).

CONCLUSIONS

Use of resistant genetic stock can be the most effective measure to minimize the damage, provided that

proper management practices are followed.

Present studies showed that different varieties of wheat tested, T21 was found significantly susceptible to

red flour beetle. In the light of such findings, prolonged storage of such most sensitive variety should be

discouraged.

Whenever, such situation prevails then there is a dire necessity to adopt adequate remedy measures against

the storage insects such as red flour beetle.

Through the methods of hybridization and genetic recombination, efforts are needed to enhance for

evolution of insects resistance and high yielding cultivars like Bhittai. Transfer of pest resistance traits

From such resistant sources to agronomic ally acceptable variety can play an important role in the IPM of

storage insects.

SUGGESTIONS

Use of resistance genetic stock can be the most effective measures to minimize the damage, provided that proper management practices are followed.