DEVELOPMENT OF HEAD MINER (Heliocheilus albipunctella) RESISTANT PEARL MILLET [Pennisetum glaucum (L.) R. Br.] HYBRIDS IN NIGER
The potential of pearl millet to address food security and poverty problems is widely acknowledged in Niger. The present study was undertaken to develop well adapted varieties that combines high yield and resistance to head miner genotypes in order to ensure food security in Niger.Three activities were conducted in this study.
The first, a participatory rural appraisal (PRA), through a survey and Focus Group Discussion sessions, was conducted to assess farmers' perceptions on production constraints and to gather information on their preferences for pearl millet varieties. From this study, pearl millet was the dominant crop across the villages surveyed. Its production in Niger is carried out under poor crop management practices. The main constraints to millet production were: drought, low soil fertility, insects/diseases, weeds and lack of equipment. Among the insects head miner was ranked the first major constraint.
Farmers use diverse criteria to select pearl millet varieties according to the environmental conditions which include resistance to diseases, insects, and drought, high grain yield, food quality, and earliness. The major traits in varieties preferred by famers were high grain yield, earliness, long panicles and food quality. Characters like length of panicle and compactness were regularly mentioned. Exploitation of hybrid vigor among different germplasm could allow development of good materials well adapted to diverse environments. The second activity was carried out to determine the best general and specific combiners based on yield, earliness and resistance to head miner.Twenty two genotypes and two checks were used for this study.
The genotypes PE01490, mil de Siaka and SOSAT_C88 were the best general combiners for yield. The non-additive effect was greater than the additive effect for most traits including grain yield, dry matter, panicle length, circumference and compactness. In addition, broad sense and narrow sense heritability estimates were above 50%. Over twenty hybrids had better than their parents and the standard checks for yield and yield components. The best among them were Mil de Siaka/HKB, SounaSenegal/HKB, SNY-03-11/HKB, PE01490/HKB, AON-644/HKB, and Mamaki/HKB for grain yield, dry matter, maturity, downy mildew resistance and panicle compactness. Some good correlations were found between variables. Grain yield and dry matter content were correlated with compactness.This meant that plants with compact panicles gave higher yield. For Genotype by environment (GXE) interaction, Mil de Siaka/HKB was stable across environments and high yielding at Maradi and Mayahi, whereas local Maradi/HKB was most stable and performed better at Tera. The third activity, the genetic study revealed that head miner damage ratings were significantly lower in the resistant parent than the susceptible parent. The damage ratings for BC1P1 were skewed towards the resistant parent P1 whereas the BC1P2 was skewed towards the susceptible parent P2. There was a positive correlation between damage rating and panicle size and the length of spikelets while there was a negative correlation between damage rating and density of spikelets. Epistatic interactions were present and highly significant for all the traits, additive x additive gene effects were involved in head miner resistance.