Pearl Millet Cultivars Research Articles

Exogenous Trehalose Treatment Enhances the Activities of Defense-Related Enzymes and Triggers Resistance against Downy Mildew Disease of Pearl Millet.

In recent years, diverse physiological functions of various sugars are the subject of investigations. Their roles in signal transduction in plant responses to adverse biotic and abiotic stress conditions have become apparent, and growing scientific evidence has indicated that disaccharides like sucrose and trehalose mediate plant defense responses in similar way as those induced by elicitors against the pathogens. Trehalose is a well-known metabolic osmoregulator, stress-protectant and non-reducing disaccharide existing in a variety of organisms, including fungi, bacteria, and plants. Commercially procured trehalose was applied to seeds of susceptible pearl millet (Pennisetum glaucum) cultivar “HB3,” and tested for its ability to reduce downy mildew disease incidence by induction of resistance. Seed treatment with trehalose at 200 mM for 9 h recorded 70.25% downy mildew disease protection, followed by those with 100 and 50 mM trehalose which offered 64.35 and 52.55% defense, respectively, under greenhouse conditions. Furthermore, under field conditions treatment with 200 mM trehalose for 9 h recorded 67.25% downy mildew disease protection, and reduced the disease severity to 32.75% when compared with untreated control which displayed 90% of disease severity. Trehalose did not affect either sporangial formation or zoospore release from sporangia, indicating that the reduction in disease incidence was not due to direct inhibition but rather through induction of resistance responses in the host. Additionally, trehalose was shown to enhance the levels of polyphenol oxidase, phenylalanine ammonia lyase, and peroxidase, which are known as markers of both biotic and abiotic stress responses. Our study shows that osmoregulators like trehalose could be used to protect plants against pathogen attacks by seed treatment, thus offering dual benefits of biotic and abiotic stress tolerance.

Improvement of DNA damage protection and antioxidant activity of biotransformed pearl millet (Pennisetum glaucum) cultivar PUSA-415 using Aspergillus oryzae MTCC 3107

Solid-state fermentation of pearl millet cultivar PUSA-415 was carried out up to 10 days by employing Aspergillus oryzae MTCC 3107 as starter culture. Aspergillus fermented millet (AFM) and unfermented millet (UFM) grains were extracted with aqueous ethanol (50%) (1:20 w/v), at 44.5 °C for 45 min. Extracts of AFM and UFM were assessed for DNA damage protection activities employing Fenton's reagent and for the presence of bioactive compounds with antioxidant potential using TPC, DPPH, ABTS, FRAP, HFRSA, CUPRAC, TAC and RPA assays. Fermentation significantly modulated the bioactive compounds, antioxidant potential and DNA damage protection activity of PUSA-415. Maximum amount of extractable TPC (18.73 mg GAE/g dwb) found in 10th day AFM sample as compared to UFM (6.11 mg GAE/g dwb). Condensed tannin contents were enhanced from 54.67 in UFM to 127.33 mg CE/100 g dwb in AFM. HPLC results further confirmed modulation of phenolic compounds viz., catechol, benzoic acid, p-coumaric acid, cinnamic acid, gallic acid and ascorbic acid resulting in enhanced antioxidant activity of AFM. Ascorbic acid was additionally modulated in AFM. This study may be helpful in designing a suitable protocol for the development of fermentation based functional food products from pearl millet that could be promising in management of chronic diseases, oxidative stress and age related ailments.

Phenolic content, antioxidant potential and DNA damage protection of pearl millet (Pennisetum glaucum) cultivars of North Indian region

Total phenolic contents, condensed tannin content, antioxidant activity and DNA damage protection of twelve pearl millet cultivars from North Indian region were assayed. All pearl millet cultivars showed considerable amount of bioactive compounds with antioxidant potential. PUSA-415 showed the presence of maximum amount of extractable total phenolic content (7.32 mg GAE/g DWB), whereas HHB-223 cultivar depicted the highest amount of condensed tannin contents (138.45 mg CE/100 g DWB). Antioxidant activity was measured using different methods viz., DPPH, ABTS, FRAP, TAC and HFRSA. A clear correlation was observed between total phenolic content and antioxidant activity of different pearl millet cultivars. The extracts of all cultivars prevented the oxidative damage to plasmid DNA (pBR322) against DNA damaging Fenton’s reagent. However, cultivars PC-383, PUSA-415, PUSA-605, PC-612 and 841-B showed prominent DNA damage protection activity. The results of this study provide a scientific basis of the traditional use of pearl millet as a natural antioxidant mitigating DNA damage.

Grain iron and zinc densities in released and commercial cultivars of pearl millet (Pennisetum glaucum)

Crop biofortification is a cost-effective and sustainable agricultural strategy to reduce micronutrient malnutrition arising from iron (Fe) and zinc (Zn) deficiencies. A large number of hybrids and open-pollinated varieties (OPVs) of pearl millet [Pennisetum glaucum (L.) R. Br.] have been released and/or commercialized in India. Eighteen OPVs and 15 high-Fe candidate hybrids were evaluated in multi-location trials for Fe and Zn density to identify those with high density of these micronutrients. The Fe density in OPVs varied from 42 mg/kg to 67 mg/kg, and Zn density from 37 mg/kg to 52 mg/kg with ICTP 8203 having the highest Fe density (67 mg/kg) followed by ICMV 221 (61 mg/kg) and AIMP 92901 (56 mg/kg). While ICTP 8203 had also the highest level of Zn density (52 mg/kg), ICMV 221 and AIMP 92901 had 45-46 mg/kg Zn density. The Fe density in hybrids varied from 46 mg/kg to 56 mg/kg and Zn density from 37 mg/kg to 44 mg/kg. Four hybrids, viz. Ajeet 38, Proagro XL 51, PAC 903 and 86M86 had the highest Fe density of 55-56 mg/kg and 39-41 mg/kg Zn density. The six commercial cultivars (2 OPVs and 4 hybrids) identified in this study with high Fe and Zn densities can be undertaken for expanded cultivation in their recommended ecologies to specifically address the Fe and Zn deficiencies in India. This study also enabled to re-define base line for Fe density at 42 mg/kg for hybrids, the most dominant cultivar type grown in India.

Effect of Drought and Nitrogen Availability on Osmotic Adjustment of Five Pearl Millet Cultivars in the Vegetative Growth Stage

AbstractGrowth of pearl millet (Pennisetum glaucum (L.) R. Br.) is affected in areas with limited and erratic rainfall, often combined with nitrogen deficiency. Therefore, effects of severe drought and nitrogen availability on mechanisms of dehydration avoidance were investigated. Five pearl millet genotypes were cultivated in soil differing in nitrogen availability, low (N1), medium (N2) or high (N3) in a climate chamber. Thirty‐five days after sowing, the plants were exposed to drought for 12 days. Drought decreased leaf area and stomatal conductance strongly and caused leaf rolling. In the youngest fully expanded leaves, drought led to an osmotic adjustment from around −0.5 to −0.9 MPa, in N1 and N2 substantially achieved by potassium accumulation. Nitrate contributed to the osmotic adjustment in N2 and N3, proline only slightly, increasingly from N1 to N2, whereas the sum of glucose, fructose and sucrose did not play a role. The dehydration independent osmotic force for water uptake (osmotic potential at full turgor) was under drought strongest at N2 and in the landrace Dembi Yellow stronger than in the cultivars Ashana and Ugandi. This contributed to the higher relative water content (RWC) of ‘Dembi Yellow’, whereas due to other factors nitrogen had no effect on the RWC.

Effects of nitrogen fertilizer on carbohydrate and protein fractions in pearl millet (Pennisetum glaucum) cultivars

Our research characterizes and quantifies carbohydrate and protein fractions of pearl millet ( Pennisetum glaucum ) cultivars at different nitrogen (N) rates and 2 sowing dates in Ceres, Goias, Brazil. A randomized block design using 3 cultivars (ADR-7010, ADR-500 and BRS-1501), 4 N rates (0, 50, 100 and 200 kg N/ha) and 2 sowing dates (December 2010 and February 2011) was employed. Two harvests were undertaken for each sowing date, when plants were 0.70 m high. There were no significant differences among cultivars in either total carbohydrates or A+B 1 , B 2 and C fractions of the carbohydrates. Total carbohydrates and their fractions were not affected by N rate nor sowing date. When protein fractionation was investigated, differences in fraction A were observed among cultivars but not in the B 1 , B 2 , B 3 and C fractions. Nitrogen rate did not affect protein fractions, but sowing date did affect fractions B 2 and B 3 . The significance of these findings in feeding animals is discussed. Keywords: Chemical composition, Cornell Net Carbohydrate and Protein System, forage, nitrogen fertilization. DOI: 10.17138/TGFT(4)47-53

Fodder production potential of pearl millet cultivars under marginal environments of Gujarat

Field experiments were carried out at Pearl millet Research Station, Junagadh Agricultural University (JAU), Jamnagar and Grassland Research Station, JAU, Dhari during Kharif 2014, to know the performance of 17 cultivars of fodder pearl millet under marginal environments of Gujarat. Significant differences were observed among the cultivars for days to 50 percent flowering, days to maturity, grain yield and green fodder yield while differences for plant height, plant population and dry fodder yield were non-significant. The locations differences were found significant for all the characters except days to 50 percent flowering and days to maturity. The cultivars x locations differences were reflected non-significant for all the traits except plant height and plant population. Days to 50 percent flowering ranged from 55 days (IP 20611) to 78 days (IP 14753). Days to maturity varied between 84 days (DFMH 30) to 100 days (IP 14294, IP 19415). The cultivar IP 19415 (294 cm) was the tallest cultivar, while, IP 14753 (223 cm) was the shortest cultivar. Grain yield was observed between 5.34 q/ha (IP 20577) to 16.68 q/ha (check PAC 981). Dry fodder yield ranged from 72 q/ha (IP 20611) to 131 q/ha (IP 10437). The cultivar IP 10151 (238 q/ha) produced the highest green fodder yield among all the cultivars followed by IP 20577 (236 q/ha) and IP 10437 (234 q/ha). Thus, these three cultivars viz ., IP 10151, IP 20577 and IP 10437 may be considered for general cultivation under marginal environments of Gujarat.

Agronomic traits, ensilability and nutritive value of five pearl millet cultivars grown in a Brazilian semi-arid region

SUMMARYPearl millet (Pennisetum glaucum(L.) R.) could play an important role as a feed source for ruminants in arid and semi-arid zones of the world owing to its high yield and drought tolerance. The current paper assessed the agronomic characteristics, ensilability, intake and digestibility of five Brazilian pearl millet cultivars (IPA Bulk1BF, BRS 1501, CMS-03, CMS-01 and BN-2) in a typical Brazilian northeastern semi-arid climate. Forage was harvested at the dough stage of grain maturity (growth stage 86 according to the BBCH scale) and ensiled under laboratory and farm conditions. Apparent digestibility of the silages was determined using 25 Santa Inês male lambs. The cultivars CMS-01, CMS-03 and BN-2 out-performed the others in terms of dry matter (DM) and digestible DM yield/ha. At DM partitioning among plant tissues, the cultivar IPA Bulk1BF had a greater DM associated with panicles and one of the greatest concentrations of organic matter, lactic acid andin vitrodry matter digestibility among the five cultivars. The cultivar BRS 1501 had greater butyric acid concentration as well as one of the highest pH values. Silage produced from BN-2 not only contained greater acetic acid concentration, but also showed one of the greatest total volatile fatty acid concentrations. There were no differences in feed intake and digestibility of nutrients and fibre fractions across all cultivars. Silage made from BN-2 resulted in greater urinary excretion of nitrogen than those produced from BRS 1501. Under the conditions of the present study, the results obtained for production of DM and digestible dry matter, and the ratio of plant fractions, indicates the possible use of these cultivars for silage production in the Brazilian semi-arid region.

Crop-climate ensemble scenarios to improve risk assessment and resilience in the semi-arid regions of West Africa

Estimation of the response of rainfed crops to heat stress and water stress must ade- quately account for the uncertainty in climatic and non-climatic factors that affect impact assess- ments. The objective of this research was to narrow the range of values characterizing the limits within which estimates are expected to fall in the diagnostics of agroclimatic risks. Assessments were made by analyzing historical observations and evaluating the influence of heat stress and rainfall variability on crop water demand, biomass and grain yields of short-cycle cultivars of pearl millet and maize. We used a wide range of consistent and practical sets of crop model ensemble analyses (based on crop management practices such as plant density, fertilization levels, early/late sowing dates and soil types) and climate model ensembles from 2 climate change hypothesis (A1b and RCP8.5) over the West African Sudan-Sahel. Recent rainfall developments show that haz- ardous intra-seasonal rainfall distribution affects crop productivity, with increased frequency and intensity of daily rainfall, false start and early cessation of the rainy season and decreasing diurnal temperature range. In 2011�2050 perspectives, relative to the 1981�2010 baseline, a slight in - crease in temperature (i.e. +0.6 to +0.8°C) combined with a stationary to moderate decrease in precipitation leads to a 10 to 15% (8 to 15%) decrease in aboveground biomass production (grain yield). When the warming is moderate (i.e. +1.4 to 1.8°C), the decline in grain yield worsens (10 to 20%), despite a slight increase in rainfall projections. At these rates of loss in crop production, resilience can be reinforced. However, it will require that climate-smart crop management prac- tices be embedded in sub-seasonal and interannual monitoring and early warning systems.

Micropropagation and Attempts to Develop RAPD Molecular Markers for Salt Tolerant Cultivars of Pearl Millet

Differences were observed among four salt tolerant cultivars of pearl millet to in vitro culture media. Among the four cultivars, Cv IP 6098 is the most salt sensitive had maximum number of multiple shoots (15)/ seed, and the more salt tolerant cvs IP 6106 and IP 22269 developed 3-6 shoots/seed while cv IP 19612 the seeds remained single shooted in MS+3.0mg/L media up to 7 months. The multiple shoots 20% of cv IP 6098, flowered in 5 months with the reduction in hormone concentration (MS+1.0 mg/L BAP) whereas, the other three cultivars did not flower under the tested conditions.
 The present study was carried to detect genetic differences among the four cultivars of pearl millet at molecular level through RAPD PCR markers. RAPD analysis was carried with 12 primers, each 10-mer, only 7 primers were amplified showed polymorphism for the four cultivars. Primer OPM 16 revealed a single unique band of approx. 485bp in the genotype IP 22269 and three polymorphic bands in the genotype IP 6106. The results were repeatable, and further studies in this direction may enable to link the single band in the genotype IP 22269 to a morphological trait or physiological condition like salt tolerance.

Micro-PIXE mapping of mineral distribution in mature grain of two pearl millet cultivars

Micro-proton-induced X-ray emission (micro-PIXE) was used to map the distribution of several nutritionally important minerals found in the grain tissue of two cultivars of pearl millet (Pennisetum glaucum (L.) R. Br.). The distribution maps revealed that the predominant localisation of minerals was within the germ (consisting of the scutellum and embryo) and the outer grain layers (specifically the pericarp and aleurone); whilst the bulk of the endosperm tissue featured relatively low concentrations of the surveyed minerals. Within the germ, the scutellum was revealed as a major storage tissue for P and K, whilst Ca, Mn and Zn were more prominent within the embryo. Fe was revealed to have a distinctive distribution pattern, confined to the dorsal end of the scutellum; but was also highly concentrated in the outer grain layers. Interestingly, the hilar region was also revealed as a site of high accumulation of minerals, particularly for S, Ca, Mn, Fe and Zn, which may be part of a defensive strategy against infection or damage. Differences between the two cultivars, in terms of the bulk Fe and P content obtained via inductively coupled plasma optical emission spectrometry (ICP-OES), concurred with the average concentration data determined from the analysis of micro-PIXE spectra specifically extracted from the endosperm tissue.

English

The aim of this study was to assess biomass production of pearl millet as a function of levels and phases of defoliation. The experiment was carried out in a protected environment at the Fazenda União experimental farm in the municipality of Nova Xavantina, MT, Brazil, in 8 dm3 capacity pots in soil classified as dystrophic red Latosol. The experimental design used was randomized blocks in a 5 × 3 + 1 factorial arrangement, with five phases of defoliation (three expanded leaves, six expanded leaves, flag leaf, booting, full flowering), three levels of defoliation (33, 66 and 99%), and an additional treatment without defoliation, with three replications. The pearl millet cultivar ADR 300 was used. Plant height, number of tillers, total dry biomass of the seed heads, and total dry biomass of the plants during the leaf rolling phase was assessed. It was observed that plant height at all levels and phases of defoliation was greater than the control. For number of tillers, a reduction was observed in the booting phase and full flowering phase at all levels of defoliation; and three expanded leaves and flag leaf phases for the levels of 66 and 99% defoliation. Total biomass of the panicle at all levels and phases of defoliation was less than the control. For total dry biomass, there was a statistical difference in relation to the control when the plants were subjected to 33% defoliation in the booting phase and full flowering phase, and 66 and 99% defoliation in all the phases. A fall in production of total dry biomass of the plant greater than 53% was observed with total elimination of the leaves during the flag leaf phase.   Key words: Leaf area, damage level, Pennisetum glaucum, no-till planting.

Isolation and Characterization of Starch from Pearl Millet (Pennisetum typhoidium) Flours

Pearl millet, an underutilized crop, is a relatively good source of nutrients and has varied uses over cereals. New applications must be explored to popularize the millet. In the present study, flour and isolated starch from pearl millet cultivars—Kalukombu and Maharashtra Rabi Bajra (MRB)—were investigated for physicochemical properties, nutritionally important starch fractions and x-ray diffraction. The yield of starch was significantly low (Kalukombu: 34.5 g/100 g and MRB: 39.4 g/100 g) with traces of non-starch components (protein, fat, and ash) indicating its purity. Starch could be classified as non-waxy type based on low amylose content (2.86–4.96 g/100 g). Low amylose lead to fragility of swollen starch granules which disintegrated easily at 65°C as observed in swelling power and solubility. Isolated starch was characterized with low water- and oil-holding capacity which could be attributed to the low protein content and absence of fiber in the starch. However, MRB starch showed higher oil uptake compared to flour, possibly due to its larger surface area that increased oil uptake. X-ray diffraction patterns showed sharp peaks at 2θ values 15 and 23º and a diffused peak at 2θ of 17 and 18º which is characteristic of A-type pattern. Low resistant starch (RS) and high readily digestible starch (RDS) content observed in the isolated starch could be attributed to the A-type pattern of starch which is more susceptible to enzyme hydrolysis and also due to elimination of structural obstruction to amylase hydrolysis during the process of starch isolation and gelatinization.

Immuno-affinity purification of PglPGIP1, a polygalacturonase-inhibitor protein from pearl millet: studies on its inhibition of fungal polygalacturonases and role in resistance against the downy mildew pathogen.

Polygalacturonase-inhibitor proteins (PGIPs) are important plant defense proteins which modulate the activity of microbial polygalacturonases (PGs) leading to elicitor accumulation. Very few studies have been carried out towards understanding the role of PGIPs in monocot host defense. Hence, present study was taken up to characterize a native PGIP from pearl millet and understand its role in resistance against downy mildew. A native glycosylated PGIP (PglPGIP1) of ~43 kDa and pI 5.9 was immunopurified from pearl millet. Comparative inhibition studies involving PglPGIP1 and its non-glycosylated form (rPglPGIP1; recombinant pearl millet PGIP produced in Escherichia coli) against two PGs, PG-II isoform from Aspergillus niger (AnPGII) and PG-III isoform from Fusarium moniliforme, showed both PGIPs to inhibit only AnPGII. The protein glycosylation was found to impact only the pH and temperature stability of PGIP, with the native form showing relatively higher stability to pH and temperature changes. Temporal accumulation of both PglPGIP1 protein (western blot and ELISA) and transcripts (real time PCR) in resistant and susceptible pearl millet cultivars showed significant Sclerospora graminicola-induced accumulation only in the incompatible interaction. Further, confocal PGIP immunolocalization results showed a very intense immuno-decoration with highest fluorescent intensities observed at the outer epidermal layer and vascular bundles in resistant cultivar only. This is the first native PGIP isolated from millets and the results indicate a role for PglPGIP1 in host defense. This could further be exploited in devising pearl millet cultivars with better pathogen resistance.

English

The potential of dry (DM) and green (GM) matter yield, plant nitrogen concentration (NC), apparent nitrogen conversion efficiency (NCE) and apparent N recovery (ANR) of pearl millet cultivars with nitrogen fertilization are analyzed. Current experiment was conducted in the municipality of Ceres GO Brazil, within the Cerrado (Brazilian savannah) biome. A 3x4x2 randomized factorial block design was employed, with three repetitions. Treatments were composed of three pearl millet cultivars (ADR-7010, ADR-500 and BRS-1501), four N doses (0, 50, 100 and 200 kgha -1 ) and two sowing times (December and February). Plants from each seeding were harvested twice at a height of 0.70 m. There was a significant effect on the interaction between cultivars and N doses. GM yield of ADR-7010 cultivar increased up to 140 kg.ha -1 of N. There was a quadratic effect of N doses on DM yield, with maximum production at 158 kg ha -1 N. The quantity of N extracted by the plants varied according to the cultivar, with BRS-1501 accumulating the highest N quantities in the shoots. Maximum NC of pearl millet shoots would be achieved with 147 kg N ha -1 . The highest NCE occurred with N doses of 50 kg ha -1 , with a DM yield of 11.60 kg per kg of applied N. ANR was also highest for N doses of 50 kg ha -1 , with a 53% maximum recovery.

B-Amino Butyric Acid ? Resistance Inducing Agent in Pearl Millet

β-amino butyric acid (BABA), applied as inducer of resistance to the seeds of susceptible cultivar of pearl millet [Pennisetum glaucum (L) R Br] against downy mildew [Sclerospora graminicola (Sacc) Schroet]. Infection offered protection to the host operative through vegetative and reproductive growth. Biochemical studies identified a close association between BABA-treatment and accumulation of defence-related proteins like phenylalanine ammonia lyase, peroxidise and β-1,3-glucanase. Studies on phenotypic host defence identified modifications in host cell wall leading to papillae formation with hydroxyproline-rich glycoproteins (HRGPs) as its major constituent. The HRGPs were identified as extensions by use of MAC 265 monoclonal antibodies. PgMPK4 (mitogen-activated protein kinase) was identified as the crucial signal transduction module signalling of pathogen cues. This increased accumulation of PgMPK4 mRNA and kinase activity in BABA-treated samples and further kinase inhibitor treatments providing critical evidence of PgMPK4 involvement in the JA- and SA mediated expression of defence genes, it may be assumed that BABA-induced resistance could be a JA/SA mediated phenomenon.

Evaluation of pearlmillet (Pennisetum glaucum)and clusterbean (Cyamopsis tetragonolobaL.) intercropping system under arid western plain zone in India

A field experiment was conducted during kharif season (July-November) of 2011 to evaluate the pearlmillet and clusterbean intercropping system in the arid region of Rajasthan. Intercropping of pearlmillet cultivar HHB-67 with clusterbean cultivar RGC-1003 in row ratio 1:3 resulted significantly maximum effective tillers per plant. Sole pearlmillet cultivar HHB-67 produced significantly maximum seed yield and had the maximum harvest index. Among intercropping treatments pearlmillet cultivar HHB-67 with clusterbean cultivarRGC-1003 in row ratio 1:1 resulted significantly maximum seed yield over other treatment.Pearlmillet cultivar Raj 171 + clusterbean cultivarRGC-1003 (1:1 row ratio)resulted in significantly maximumstover and biological yield. Intercropping of pearlmillet cultivar HHB-67 + clusterbean cultivarRGC-986 in row ratio 1:3 was superior to all the intercropping treatments in terms of PMEY, net returns and B:C ratio. But LER ofpearlmillet cultivar HHB-67 + clusterbean cultivarRGC-986 in row ratio 2:2 was maximum among all the treatments.

The pearl millet mitogen-activated protein kinase PgMPK4 is involved in responses to downy mildew infection and in jasmonic- and salicylic acid-mediated defense.

Plant mitogen-activated protein kinases (MPKs) transduce signals required for the induction of immunity triggered by host recognition of pathogen-associated molecular patterns. We isolated a full-length cDNA of a group B MPK (PgMPK4) from pearl millet. Autophosphorylation assay of recombinant PgMPK4 produced in Escherichia coli confirmed it as a kinase. Differential accumulation of PgMPK4 mRNA and kinase activity was observed between pearl millet cultivars 852B and IP18292 in response to inoculation with the downy mildew oomycete pathogen Sclerospora graminicola. This increased accumulation of PgMPK4 mRNA, kinase activity as well as nuclear-localization of PgMPK protein(s) was only detected in the S. graminicola resistant cultivar IP18292 with a ~tenfold peak at 9h post inoculation. In the susceptible cultivar 852B, PgMPK4 mRNA and immuno-detectable nuclear PgMPK could be induced by application of the chemical elicitor β-amino butyric acid, the non-pathogenic bacteria Pseudomonas fluorescens, or by the phytohormones jasmonic acid (JA) or salicylic acid (SA). Furthermore, kinase inhibitor treatments indicated that PgMPK4is involved in the JA- and SA-mediated expression of three defense genes, lipoxygenase, catalase 3 and polygalacturonase-inhibitor protein. These findings indicate that PgMPK/s contribute to pearl millet defense against the downy mildew pathogen by activating the expression of defense proteins.

Development of SCAR marker associated with downy mildew disease resistance in pearl millet (Pennisetum glaucum L.).

Pearl Millet is an important crop coarse grain cereal crop in the semi arid tropics which is extremely susceptible to oomycete plant pathogen Sclerospora graminicola causing downy mildew (DM) disease. The aim of the current study is to breed resistance against downy mildew disease into high yielding cultivars of pearl millet. Hence, in the present work a sequence characterized amplified region (SCAR) marker was developed as a molecular screening tool to identify DM resistance source and presented here. Of the 27 inter simple sequence repeats (ISSR) decamer primers used to identify polymorphism amongst pearl millet genotypes ICMR-01007 (P1) and ICMR-01004 (P2) and their populations (F1 and F2), only one primer pair ISSR-22 produced polymorphic bands on ICMR-01004 producing 1.4 kb size. The PCR amplification of 1.4 kb band was found tightly linked to the resistant line of ICMR-01004 and also in F2 segregation population was in the ratio 3:1. This band was cloned, sequenced and candidate SCAR primer (SCAR ISSR 863 ) was designed. Segregant analysis of their F2 progeny revealed that the SCAR ISSR 863 marker was linked to downy mildew resistance linkage group (χ(2) 3:1 = 0.86, P = 0.22) with a genetic distance of 0.72 cM. This SCAR marker was further validated using diverse pearl millet lines of India and Africa. Results indicated that the SCAR ISSR 863 band was amplified in all the seven resistant lines and were absent in five susceptible lines. The confirmation of the ISSR-derived SCAR marker in different genetic backgrounds of pearl millet lines suggests that this marker can be exploited for DM resistance screening in pearl millet breeding programs.

Eficiência da fertilização fosfatada e nitrogenada em cultivares de milheto

Objetivou-se avaliar a produção de massa seca (PMS) da planta inteira, determinar o nitrogênio contido (NC) no tecido da planta, a eficiência de conversão aparente do nitrogênio (ECAN) e a recuperação aparente do nitrogênio (RAN) de cultivares de milheto forrageiro submetidos às fontes de fósforo e doses de nitrogênio. O experimento realizado no ano agrícola de 2008 constou de um fatorial 2 × 3 × 4, em arranjo de blocos completos ao acaso, com quatro repetições. Os tratamentos foram constituídos pelos cultivares ADR- 7010; ADR-500 e BRS-1501, pelas fontes de fósforo superfosfato simples (SS) e termofosfato (TF), as quais foram aplicadas na dose de 70 kg.ha-1 e doses de N (0; 40; 80 e 160 kg.ha-¹ sob forma de uréia). A análise estatística revelou ausência de interações significativas entre as variáveis. Entre os cultivares avaliados, a melhor produção (P<0,05) foi a do cultivar ADR-7010 (1175,9 kg.ha-1 de MS), o superfosfato simples apresentou resultados superiores. O incremento de N promoveu aumentos produtivos, a sucessão dos cortes reduziu a produção de MS. Houve diferença (P<0,05) para NC, sendo que, à medida que as doses de N foram elevadas, houve acréscimo linear do NC com valor máximo de 42,7 kg de N extraído. A ECAN e RAN diminuiu em função do acréscimo do nutriente, com valores máximos de 10,7 kg.ha-1 e 33,4% na dose referente a 40 kg.ha-1 de N. A fertilização nitrogenada promoveu incrementos na produção de massa seca dos cultivares de milheto.