Effect of water availability pattern on yield of pearl millet in semi-arid tropical environments

Throughout much of the semi-arid tropics, fluctuations in grain yield can largely be attributed to differences in timing and intensity of drought stress. Since seasonal rainfall in these environments is often poorly related to grain yield, the aim of this paper was to establish a relationship between water availability and grain yield for pearl millet (Pennisetum glaucum (L.) R. Br.), grown across 24 semi-arid tropical environments in India. We used a simple soil water budget to calculate a water satisfaction index (WSI) throughout the season. The cumulative WSI at maturity explained 76% of the variance in grain yield. This was three times as much as explained by actual rainfall, because WSI accounted for differences in water losses and pan evaporation. A classification of environments into four groups of water availability patterns explained 75% of the environmental sum of squares for grain yield. For a subset of 13 environments, environmental differences in grain number could also be explained by water availability patterns, whereas differences in grain mass were related to both water availability and temperature. Our results indicate that cumulative WSI, which is an integrated measure of plant-available water, can provide an adequate estimation of the environmental potential for yield in environments where grain yield is mainly limited by variable availability of water

Genetic variation and diversity of pearl millet [Pennisetum glaucum (L.)] genotypes assessed for millet head miner, Heliocheilus albipunctella resistance, in West Africa

Pearl millet (Pennisetum glaucum L.), the major source of minerals and dietary energy for people living in the semi-arid regions of Sahel, is regularly damaged by millet head miner, Heliocheilus albipunctella. In order to identify the plant-based resistance sources for millet head miner along with high grain Fe and Zn, we have screened forty pearl millet genotypes, using an artificial infestation method. Analysis of variance revealed significant differences in the genotypes tested for head miner resistance. The genotypes Gamoji, ICMP 177001, ICMP 177002, ICMV 177003, ICMV IS 90311, LCIC9702, Souna 3, ICMV IS 94206 and PE08043 exhibited antibiosis resistance mechanism to Heliocheilus albipunctella with appreciable agronomy and grain yield when compared with the susceptible check ICMV IS 92222. The genotypes Faringuero, ICMV 167005, ICMV IS 99001, Sadore local, SOSAT-C88, and ICMP 177004 exhibited tolerance to head miner damage with good per se performance. The genotypes ICMP 177001, ICMP 177002, ICMV 177003, and Moro exhibited resistance to millet head miner and had consistent grain Fe content across seasons (ranging from 44 to 70 ppm). Association between the head miner resistance and morphological traits showed a positive and significant correlation of larval production index (%) with head miner damage (r = 0.59**). Grain Fe and Zn contents exhibited negative association with panicle length and grain yield indicating proper care should be taken in breeding for these traits. Hence, the identified resistance sources can be effectively utilized in breeding head miner resistant pearl millet OPV’s/ hybrids, with high grain yield including Fe and Zn concentrations, to overcome the hunger and malnutrition seen in populations living in the semi-arid tropics

Genomic Approaches to Enhance Stress Tolerance for Productivity Improvements in Pearl Millet

Pearl millet [Pennisetum glaucum (L.) R. Br.], the sixth most important cereal crop (after rice, wheat, maize, barley, and sorghum), is grown as a grain and stover crop by the small holder farmers in the harshest cropping environments of the arid and semiarid tropical regions of sub-Saharan Africa and South Asia. Millet is grown on ~31 million hectares globally with India in South Asia; Nigeria, Niger, Burkina Faso, and Mali in western and central Africa; and Sudan, Uganda, and Tanzania in Eastern Africa as the major producers. Pearl millet provides food and nutritional security to more than 500 million of the world’s poorest and most nutritionally insecure people. Global pearl millet production has increased over the past 15 years, primarily due to availability of improved genetics and adoption of hybrids in India and expanding area under pearl millet production in West Africa. Pearl millet production is challenged by various biotic and abiotic stresses resulting in a significant reduction in yields. The genomics research in pearl millet lagged behind because of multiple reasons in the past. However, in the recent past, several efforts were initiated in genomic research resulting into a generation of large amounts of genomic resources and information including recently published sequence of the reference genome and re-sequencing of almost 1000 lines representing the global diversity. This chapter reviews the advances made in generating the genetic and genomics resources in pearl millet and their interventions in improving the stress tolerance to improve the productivity of this very important climate-smart nutri-cereal

Association analysis of low-phosphorus tolerance in West African pearl millet using DArT markers

Pearl millet [Pennisetum glaucum (L.) R. Br.] is a food security crop in the harshest agricultural regions of the world. While low soil phosphorus (P) availability is a big constraint on its production, especially in West Africa (WA), information on genomic regions responsible for low-P tolerance in pearl millet is generally lacking. We present the first report on genetic polymorphisms underlying several plant P-related parameters, flowering time (FLO) and grain yield (GY) under P-limiting conditions based on 285 diversity array technology markers and 151 West African pearl millet inbred lines phenotyped in six environments in WA under both high-P and low-P conditions. Nine markers were significantly associated with P-related traits, nine markers were associated with FLO, whereas 13 markers were associated with GY each explaining between 5.5 and 15.9 % of the observed variation. Both constitutive and adaptive associations were observed for FLO and GY, with markers PgPb11603 and PgPb12954 being associated with the most stable effects on FLO and GY, respectively, across locations. There were a few shared polymorphisms between traits, especially P-efficiency-related traits and GY, implying possible colocation of genomic regions responsible for these traits. Our findings help bridge the gap between quantitative and molecular methods of studying complex traits like low-P tolerance in WA. However, validation of these markers is necessary to determine their potential applicability in marker-assisted selection programs targeting low-P environments, which are especially important in WA where resource-poor farmers are expected to be the hardest hit by the approaching global P crisis

Towards understanding the traits contributing to performance of pearl millet open-pollinated varieties in phosphorus-limited environments of West Africa

Aims Pearl millet [Pennisetum glaucum (L.) R. Br.] open-pollinated varieties, which are the predominant cultivars, have never been systematically evaluated for adaptation to low-soil phosphorus (P), a major constraint on pearl millet production in West Africa (WA). Methods We evaluated grain yield (GY), flowering time (FLO), harvest index (HI), and residual grain yields (RGY) of 102 open-pollinated varieties from WA under low-P (−P) and high-P (+P) field conditions in six environments of WA. In addition, PE-related traits of the varieties were evaluated at early growth stage in a pot experiment. Results Significant genetic variation was observed for GY, FLO, HI and PE-related traits. P-efficient varieties had higher yield under −P conditions. Varietal performance under −P varied across environments depending on FLO, relative flowering delay under −P (FD) and RGY measured in the field. Low-P-susceptible varieties had higher FLO, lower HI than low-P-tolerant varieties. Response to direct selection under −P field conditions was 20.1 g m−2, whereas indirect selection response under +P was 16.3 g m−2. Conclusions Selection under −P field conditions while taking into account seasonal variations for FLO, FD and PE is expected to be important for improving GY specifically targeting −P environments in WA

Conventional and Molecular Breeding Approaches for Biofortification of Pearl Millet

Pearl millet [Pennisetum glaucum (L.) R. Br.] is an essential diet of more than 90 million people in the semi-arid tropics of the world where droughts and low fertility of soils cause frequent failures of other crops. It is an important nutri-rich grain cereal in the drier regions of the world grown on 26 mha by millions of farmers (IFAD 1999; Yadav and Rai 2013). This makes pearl millet the sixth most important crop in the world and fourth most important food crop of the India, next to rice, wheat, and maize with annual cultivation over an area of ~8 mha. Pearl millet is also primary food crop in sub-Saharan Africa and is grown on 15 mha (Yadav and Rai 2013). The significant increase in productivity of pearl millet in India is attributed to development and adoption of hybrids of early to medium duration maturity. More than 120 diverse hybrids/varieties have been released till date for various production environments. The heterosis breeding and improved crop management technologies increased productivity substantially achieving higher increased production of 9.80 mt in 2016–2017 from 2.60 mt in 1950–1951 in spite of declined of area under the crop by 20–30% over last two decades (Yadav et al. 2012)

Assessment of drought resistance in pearl millet (Pennisetum americanum (L.) Leeke). II. Estimation of genotype response to stress

Yield trials of advanced lines of pearl millet were grown under midseason (panicle initiation to flowering) and terminal (flowering to maturity) drought stresses in the dry seasons of 1981, 1982, and 1983 in Patancheru, India. Grain yield and its components were severely reduced by the terminal stress, but were little affected by the midseason drought, as there was compensation by later tillers for yield lost on the earlier shoots. Grain yields for irrigated control, midseason stress and terminal stress treatments were resp., 0.230, 0.218 and 0.103 kg/m2 in 1981, 0.246, 0.257 and 0.109 kg/m2 in 1982, and 0.298, 0.249 and 0.097 kg/m2 in 1983. The major factor determining grain yield of a genotype in both stress treatments was its time to flowering. Hence yield to yield component relationships under stress were a result of yield component to phenology relationships. Yield potential (measured in an irrigated treatment in the same field) was generally positively related to yield under stress, but accounted for a much smaller fraction of yield variation than time to flowering. These two factors together accounted for more than 50% of the total variation in grain yield under stress, suggesting that genotype response (drought resistance/susceptibility) was a secondary rather than a primary factor in differences in yield under stress among the genotypes tested

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Not AvailableAbstract The paper reports on the variations in organic matter digestibility (OMD), organic matter intake (OMI), digestible organic matter intake (DOMI) and nitrogen (N) balances of 40 pearl millet stover fed to sheep ad libitum and investigated relationships between these in vivo variables and morphological, chemical and in vitro stover quality traits. Highly significant differences (P<0.0001) were observed for all in vivo variables. Plant height and stem diameter were consistently significantly (at least P=0.0002) inversely related to OMD, OMI, DOMI and N balance. Except for OMD (P=0.16) stover nitrogen content was significantly (at least P=0.0005) positively related to OMI, DOMI and N balance. The fiber constituents neutral (NDF) and acid (ADF) detergent fiber and acid detergent lignin (ADL) were consistently inversely related to OMD, OMI, DOMI and N balance. (at least P=0.0005). Stover in vitro digestibility, metabolizable energy content and extent and rate of in vitro gas production were highly positively (at least P<0.0009) related to the in vivo variables while lag and half time of in vitro gas production were negatively associated (at least P=0.0004) with the in vivo variables. Combined morphological, chemical and in vitro variables in stepwise multiple regressions accounted for 70 to 84%% of the variations observed in the in vivo variables. Application of stringent cross validation procedures reduced the variation in OMD, OMI, DOMI and N balance accounted for by the combined morphological, chemical and in vitro variables mostly moderately to 71, 49, 79 and 76%, respectively. Relatively simple traits can predict stover quality in breeding programs for dual-purpose pearl millet cultivarsNot Availabl