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Feb 2017

Genetic variability for fodder quality traits in sorghum under different water regimes

Kanuganahalli V1, Kodukula P2, Devulapalli R2, Deshpande S1*, Vadez V1, Blümmel M 2

Traits Mean (±SE) Range σ2g h2

Year 2012 2013 2015 2012 2013 2015 2012 2013 2015 2012 2013 2015ME 7.23 (0.55) 7.06 (0.81) 6.667 (0.64) 6.83-7.70 6.69-7.70 6.23-7.30 0.02 0.07 0.04 0.47 0.66 0.67IVOMD 48.40 (3.24) 48.50 (4.59) 46.42 (3.77) 45.75-51.00 46.18-52.01 43.86-50.47 0.72 2.11 1.42 0.40 0.60 0.60PH 156.26 (85.79) 179.53 (75.64) 179.31 (109.70) 105.28-238.05 127.50-243.89 115.00-253.88 1189.30 401.02 1897.50 0.96 0.42 0.94DFF 72 (13.41) 85 (13.68) 60 (2.74) 55-85 67-101 54-72 52.98 0.00 3.94 0.96 0.00 0.18TW 2.45 (1.29) 3.00 (1.19) 2.65 (1.65) 1.59-3.70 2.16-4.70 1.70-4.16 0.26 0.00 0.43 0.91 0.04 0.94SY 4286 (3299) 4316 (2489) 5053 (4568) 2170-8369 2538-7188 2920-10018 1493322 437287 2646980 0.86 0.42 0.76GY 3315 (1358) 2759 (739) 3382 (1560) 1895-4054 2260-3408 1950-4422 131729 0.00 306010 0.42 0.00 0.75

Traits Mean (±SE) Range σ2g σ2g×e h2

MEC 7.15 (0.76) 8.22-7.11 0.05 0.00 0.83S 6.80 (0.71) 7.34-6.51 0.02 0.08 0.41

IVOMDC 48.81 (4.33) 54.03-47.71 1.70 0.12 0.81S 46.49 (6.83) 49.12-43.77 0.64 2.87 0.34

PHC 177.23 (123.78) 238.88-115.55 1621.10 209.89 0.95S 166.16 (88.91) 237.20-95.00 622.11 623.25 0.71

DFFC 72 (20.63) 60-82 10.40 32.71 0.44S 74 (20.53) 69-83 0.00 29.07 0.00

TWC 2.94 (1.92) 4.30-1.80 0.38 0.06 0.93S 2.45 (1.32) 3.47-1.38 0.11 0.18 0.58

SYC 5848 (4835) 10555-3327 1913534.10 1397837.40 0.74S 3256 (2479) 6184-995 375264.90 620475.50 0.55

GYC 3504 (1388) 4612-2424 102785.20 191186.90 0.48S 2800 (1082) 4238-1366 8481.60 258463.70 0.07

Introduction: Sorghum is grown for food and fodder

in marginal environments highly water use efficient crop exhibits drought tolerance

Fodder demands makes breeding forquantity and quality improvementessential

Digestibility is considered as key factordetermining the fodder quality

One percentage variation in stoverdigestibility increases output by 6 to 8%

Conclusion: No significant association between quality and yield traits were observed Opportunity for simultaneous improvement for yield and fodder quality A parental set of ICSV1 and ICSV700 with contrasting values across all seasons

for IVMOD under different was identified Utilized for further genetic mapping of the fodder quality traits in sorghum.

Materials and Methods:24 sorghum lines were screened for drought for 3 years in post rainy season invertisol following alpha lattice design in three replications. The biomass fromthe plot was harvested, dried, ground and passed through 1mm sieve, lateranalysed in Near Infrared Spectroscopy (NIRS), calibrated for this experimentagainst conventional wet laboratory analyses (IVOMD). The statistical packageof SAS (1988) was used for analysis of variance (SAS GLM procedure) forestimation of simple correlations between laboratory quality and agronomictraits.Result: The stress has caused a significant reduction for the traits under study

except flowering. The flowering is delayed by 9 days under stress conditions. The percent reduction under stress for ME is 10.70%, for IVOMD is 9.08%,

for SY is 41.38% and TW is 19.30% except for flowering which increasedunder stress by 15% causing a delay in flowering.

No significant correlation between yield and any quality traits wereobserved

PH and SY are positively correlated (0.69@P=5%) PH has heritability of 0.71, TW has 0.71 and SY has 0.55, under stress Variations for traits under study was observed across years IVOMD has shown an average of 48.40 (3.24) in 2012, 48.50 (4.59) in 2013

and 46.42 (3.77) in 2015 TW has an average of 2.45 (1.29) in 2012, 3.00 (1.19) in 2013 and 2.65

(1.65) in 2015. Flowering varies from 55 to 100 days across all the years

Abstract: Sorghum is grown as a dual purpose crop yielding food (grain) and fodder (stover) in marginal environments of Asia and Sub-Saharan Africa.Application of genomics and trait discovery tools in breeding program can expedite genetic improvement of fodder quality. Earlier reports suggested that adifference of one percentage unit in stover digestibility increases livestock output of 6 to 8%. To characterize fodder quality traits in sorghum and to identifygenomic regions related to t[hose traits, a set of mapping population parents (24) were evaluated under two water regimes (control and stress) over 3 years atICRISAT-Patancheru. In vitro organic matter digestibility (IVOMD%) – a key stover quality trait, test weight (TW-g), stalk yield (SY-Kg/ha) and grain yield (GY-Kg/ha) recorded significant variation across genotype, treatment, year and interaction effects. Across season analyses revealed a range of 45.8% to 50.4% forIVOMD, variation from 1.9g to 4.1g for TW. The SY and GY recorded a mean value of 4552 Kg/ha and 3152 Kg/ha, across years. While heritability estimatesacross seasons were on higher side for TW (0.85), SY (0.77) and IVOMD (0.70), it was lower for GY (0.39). A positive correlation of 0.63 and 0.79 was observedfor SY – IVOMD and plant height (PH) - SY, respectively. This further implied that an opportunity exists for simultaneous improvement in both yield and fodderquality. We identified a parental set of ICSV1 and ICSV700 having consistently contrasting values across all seasons for IVMOD for further genetic mapping of thefodder quality traits in sorghum.

ME: Metabolizable Energy; IVOMD: In Vitro Organic Matter Digestibility; PH: Plant height (cm), DFF: Days to Fifty percent Flowering; TW: 100 seed weight (g); SY: Stalk Yield (Kg/ha); GY: Grain Yield (Kg/ha); σ2g: Genotypic variance; h2: Narrow Sense Heritability

C: Control; S: Stress (Drought); σ2g : Genotypic variance; σ2g×e : Genotypic and environment variances; h2: Narrow Sense Heritability; ME: Metabolizable Energy; IVOMD: In Vitro Organic Matter Digestibility; PH: Plant height (cm), DFF: Days to Fifty percent Flowering TW: 100 seed weight (g); SY: Stalk Yield (Kg/ha); GY: Grain Yield (Kg/ha)

Table 1: Statistical variations across control and stress for key quality andagronomic traits

Table 3: Statistical variations across three years for key quality and agronomic traits

List of Genotype296B IS41397-3

BTx623 IS8219Bulk Y IS9830E 36-1 M 35-1

ICSB370-2-9 N13ICSB377 Parbhani Moti

ICSR93024 PB15220-1ICSV1 PB15881-3

ICSV700 PVK 801ICSV745 S35

ICSV93046 SP 2417IS18551 SP 39105

Traits ME IVOMD DFF PH TW SY GYTreatment C S C S C S C S C S C S C S

ME C 1 0.78 0.99 0.73 0.06 0.01 0.63 0.57 0.53 0.41 0.62 0.54 0.18 0.30S 0.78 1 0.77 0.99 0.11 0.06 0.60 0.48 0.39 0.35 0.62 0.64 0.03 0.17

IVOMD C 0.99 0.77 1 0.73 0.04 0.00 0.60 0.55 0.55 0.42 0.58 0.52 0.14 0.31S 0.73 0.99 0.73 1 0.13 0.09 0.52 0.40 0.41 0.34 0.58 0.60 -0.01 0.13

DFF C 0.06 0.11 0.04 0.13 1 0.47 -0.01 -0.15 -0.1 -0.28 0.31 0.27 0.48 -0.01S 0.01 0.06 0.00 0.09 0.47 1 0.06 -0.12 -0.23 -0.30 0.36 0.31 0.44 0.05

PH C 0.63 0.60 0.60 0.52 -0.01 0.06 1 0.90 0.03 0.12 0.81 0.84 0.19 0.29S 0.57 0.48 0.55 0.40 -0.15 -0.12 0.90 1 0.12 0.29 0.63 0.69 0.23 0.49

TW C 0.53 0.39 0.55 0.41 -0.10 -0.23 0.03 0.12 1 0.81 0.12 -0.05 -0.29 0.07S 0.41 0.35 0.42 0.34 -0.28 -0.30 0.12 0.29 0.81 1 0.11 0.00 -0.25 0.33

SY C 0.62 0.62 0.58 0.58 0.31 0.36 0.81 0.63 0.12 0.11 1 0.87 0.35 0.18S 0.54 0.64 0.52 0.60 0.27 0.31 0.84 0.69 -0.05 0.00 0.87 1 0.35 0.27

GY C 0.18 0.03 0.14 -0.01 0.48 0.44 0.19 0.23 -0.29 -0.25 0.35 0.35 1 0.46S 0.30 0.17 0.31 0.13 -0.01 0.05 0.29 0.49 0.07 0.33 0.18 0.27 0.46 1

Table 2: Correlation table across control and stress for key quality and agronomic traitsRED: Significant P@1%; BLUE: Significant P@5%

1International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India, 2International Livestock Research Institute, Hyderabad, India