HUBUNGAN KEKUATAN OTOT LENGAN DAN POWER OTOT TUNGKAI TERHADAP KEMAMPUAN RENANG GAYA DADA JARAK 20 METER PADA MAHASISWA PENJASKESREK FKIP UNSYIAH ANGKATAN 2011

Banda Ace

Stay green physiological capacity of drought tolerant maize inbred lines

Stay green is the ability of a plant to maintain photosynthetically functional green leaf area for longer periods, even under excessive water stress. This study was done to establish the physiological capacity of Ugandan drought tolerant maize inbred lines to stay green under water shortage conditions using various stay green physiological determinants. Seventy-six maize inbred lines characterised for drought tolerance by CIMMYT, were planted under a rain out shelter, with a well-watered control (WW) and excessive water-stress treatments applied at six weeks after planting (6 WAP) and eight weeks after planting (8 WAP). The most maintained stay green physiological determinants under excessive water-stress were non-photosynthetic quench (NPQt) and leaf pigmentation per unit leaf area (RC: LAUG) with inbred lines CELQ15028 and CELQ15022 showing the highest maintenance for the two parameters, respectively. The highest level of variation for quantum yield of photosystem II activity (Phi2) and NPQt among inbred lines was at 40 and 60 days after flowering, respectively. Phi2 was negatively correlated to NPQt but positively correlated to the linear electron flow (LEF); while NPQt had a significantly negative correlation with LEF. This study established that these drought tolerant maize inbred lines have moderate stay green physiological capacity, with inbred line CEL15027 performing the best.Le retard de s\ue9nescence du feuillage (\u201cstay green\u201d) est la capacit\ue9 d\u2019une plante \ue0 maintenir une surface foliaire verte photosynth\ue9tiquement fonctionnelle pendant de plus longues p\ue9riodes, m\ueame en cas de stress hydrique excessif. Cette \ue9tude a \ue9t\ue9 r\ue9alis\ue9e pour \ue9tablir la capacit\ue9 physiologique des lign\ue9es consanguines de ma\uefs ougandaises tol\ue9rantes \ue0 la s\ue9cheresse \ue0 retard de s\ue9nescence du feuillage (\u201cstay green\u201d) dans des conditions de p\ue9nurie d\u2019eau en utilisant divers d\ue9terminants physiologiques de retard de s\ue9nescence du feuillage (\u201cstay green\u201d). Soixante-seize lign\ue9es consanguines de ma\uefs caract\ue9ris\ue9es pour la tol\ue9rance \ue0 la s\ue9cheresse par le CIMMYT ont \ue9t\ue9 plant\ue9es sous un abri anti-pluie, avec un contr\uf4le bien arros\ue9 (WW) et des traitements contre le stress hydrique excessif appliqu\ue9s six semaines apr\ue8s la plantation (6 WAP) et huit semaines apr\ue8s la plantation. (8 WAP). Les d\ue9terminants physiologiques verts de s\ue9jour les plus maintenus sous un stress hydrique excessif \ue9taient la trempe non photosynth\ue9tique (NPQt) et la pigmentation des feuilles par unit\ue9 de surface foliaire (RC: LAUG) avec les lign\ue9es consanguines CELQ15028 et CELQ15022 pr\ue9sentant le maintien le plus \ue9lev\ue9 pour les deux param\ue8tres respectivement. Le niveau de variation le plus \ue9lev\ue9 du rendement quantique de l\u2019activit\ue9 du photosyst\ue8me II (Phi2) et du NPQt parmi les lign\ue9es consanguines \ue9tait respectivement \ue0 40 et 60 jours apr\ue8s la floraison. Phi2 \ue9tait corr\ue9l\ue9 n\ue9gativement au NPQt mais positivement corr\ue9l\ue9 au flux d\u2019\ue9lectrons lin\ue9aire (LEF) tandis que NPQt avait une corr\ue9lation significativement n\ue9gative avec le LEF. Cette \ue9tude a \ue9tabli que ces lign\ue9es consanguines de ma\uefs tol\ue9rantes \ue0 la s\ue9cheresse avaient une capacit\ue9 physiologique \ue0 retard de s\ue9nescence du feuillage (\u201cstay green\u201d) mod\ue9r\ue9e, la lign\ue9e consanguine CEL15027 a mieux fonctionn\ue9

Metagenomic analysis of viruses associated with maize lethal necrosis in Kenya

Background: Maize lethal necrosis is caused by a synergistic co-infection of Maize chlorotic mottle virus (MCMV) and a specific member of the Potyviridae, such as Sugarcane mosaic virus (SCMV), Wheat streak mosaic virus (WSMV) or Johnson grass mosaic virus (JGMV). Typical maize lethal necrosis symptoms include severe yellowing and leaf drying from the edges. In Kenya, we detected plants showing typical and atypical symptoms. Both groups of plants often tested negative for SCMV by ELISA. Methods: We used next-generation sequencing to identify viruses associated to maize lethal necrosis in Kenya through a metagenomics analysis. Symptomatic and asymptomatic leaf samples were collected from maize and sorghum representing sixteen counties. Results: Complete and partial genomes were assembled for MCMV, SCMV, Maize streak virus (MSV) and Maize yellow dwarf virus-RMV (MYDV-RMV). These four viruses (MCMV, SCMV, MSV and MYDV-RMV) were found together in 30 of 68 samples. A geographic analysis showed that these viruses are widely distributed in Kenya. Phylogenetic analyses of nucleotide sequences showed that MCMV, MYDV-RMV and MSV are similar to isolates from East Africa and other parts of the world. Single nucleotide polymorphism, nucleotide and polyprotein sequence alignments identified three genetically distinct groups of SCMV in Kenya. Variation mapped to sequences at the border of NIb and the coat protein. Partial genome sequences were obtained for other four potyviruses and one polerovirus. Conclusion: Our results uncover the complexity of the maize lethal necrosis epidemic in Kenya. MCMV, SCMV, MSV and MYDV-RMV are widely distributed and infect both maize and sorghum. SCMV population in Kenya is diverse and consists of numerous strains that are genetically different to isolates from other parts of the world. Several potyviruses, and possibly poleroviruses, are also involved

The Potential of Cultural and Chemical Control Practices for Enhancing Productivity of Banana Ratoons

A study of the effect of plant population, fertiliser application, number of suckers retained per stool and desuckering time on the 5th and 6th banana ratoons was conducted on Kibuzi (AAA-EA) plantation from October 2000 to December 2002. The plantation had earlier (October 1999 to October 2000) received poor management which resulted in high infestation by weevils and nematodes, small bunches and low yields. The study was accomplished in two experiments. In the first experiment, the original spacings of 2.5x2.5m (1,600 plants ha-1), 3x3m (1,111 plants ha-1) and 3.75x3.75m (711 plants ha-1) were maintained in main plots when the plantation was redesigned into a split plot experiment for each original plot with the sub-plots containing N/K fertilisers applied at the rates of 0/0, 50/100 and 100/200-kg ha-1 yr-1 in two splits since these nutrients were limiting. Phosphorus was applied as a blanket cover at 75 kg P ha-1 yr-1. Three suckers were maintained per stool and extra suckers removed using a hand hoe giving a population of 4800, 3,333 and 2133 plants ha-1 at 2.5x2.5m, 3x3m and 3.75x3.75m, respectively. The second experiment originally at a spacing of 3x3 m had a split plot design with 2 and 3 suckers per stool maintained in the main plots and extra suckers removed at time intervals of 1 month, 2 months and 3 months in the sub-plots. Curaterr 5G (carbofuran) and Agro-chlordi (chlorpyrifos/dimethoate mixture) were applied in all the sub-plots at the beginning of both experiments (Oct. 2000) to control banana weevils and nematodes. Results of effect of plant population and fertiliser application showed that in the 5th ratoon, plant population had no significant influence on growth characters of flowering plants but flowering to harvesting duration and yield ha-1 significantly (P < 0.05) decreased with decrease in plant population. The 6th ratoon had a significant (P < 0.05) decrease in growth characters of plant height, flowering to harvesting duration, and a significant (P < 0.05) increase in yield components of hands per bunch and finger girth with decrease in plant population. Despite fertiliser application at N50K100 and N100K200, there was a remarkable decline in the 6th ratoon due to toppling and snapping following windy weather. Results of number of suckers retained per stool and desuckering time indicated higher growth parameters in the 5th than the 6th ratoon due to population reduction owing to high mat, weevil and nematode infected plants being vulnerable to wind damage. Unlike the 5th ratoon, the 6th ratoon had significant (P < 0.05) decrease in all growth parameters with increase in desuckering time. Better economic benefits were observed from early desuckering and N50K100 treatments in both ratoons. Although curaterr 5G significantly (P < 0.05) reduced nematode populations resulting in reduced necrosis index and agro-chlordi insecticide treatment following curaterr 5G treatment effectively eliminated weevils from the ratoons, the plants could not effectively recover their rooting system since the corms had been damaged beyond recovery. Thus, were infestation of banana weevils and nematodes is apparent, it is critical to initiate application of control interventions before the 5th ratoon. Besides, results of the study indicate that its better to establish new plantations rather making efforts to rehabilitate long neglected plantations.Une étude de l&apos;effet de la population de plantes, l&apos;application des engrais, le nombre des rejets retenues par plante mère et le temps de l&apos;œilletonnage sur la 5eme et 6eme souche était conduite sur plantation de Kibuzi (AAA-EA) à partir d&apos;Octobre 2000 à Décembre 2002. La plantation avait précédemment (Octobre 1999 à Octobre 2000) reçu une mauvaise gestion résultant d&apos;une infestation élevée des charançons et nématodes, des petites grappes et faibles rendements. L&apos;étude était accomplie en deux expériences. Dans la première expérience, les espacement originaux de 2,5 x 2,5 m (1600 plantes ha-1), 3 x 3 m (1111plantes ha-1) et 3,75 x 3,75 m (711 plantes ha-1) étaient maintenus dans les parcelles principales lorsque la plantation était redessinée en parcelle expérimentale divisée pour chaque parcelle originale avec des sous parcelles contenant les fertilisants N/K appliqués aux taux de 0/0, 50/100 et 100/200 kg ha-1 annee-1 en deux fentes parce que ces substances nutritives étaient limitées. Le phosphore était appliqué comme couverture à 75 kg P ha-1 annee-1. Trois rejets étaient maintenus par plante mère et des rejets de surplus enlevés en utilisant une houe manuelle donnant une population de 4800, 3333 et 2133 plantes ha-1 à 2,5 x 2,5 m, 3 x 3 m et 3,75 x 3,75 m respectivement. La seconde expérience originalement à espacement de 3 x 3 m avait un dessin de parcelle divisée avec 2 à 3 rejets par plante mère maintenu dans les parcelles principales et les rejets de surplus enlevés à l&apos;intervalle de temps de 1 mois, 2 mois et 3 mois dans les sous parcelles. Le curateur 5G (carbofuran) et l&apos;Agro-chlordi (mélange chlorpyrifos/dimethoate) étaient appliqués dans toutes les sous parcelles au début de toutes les deux expériences (octobre 2000) pour contrôler les charançons et nématodes dans le champs de banane. Les résultats de l&apos;effet de la population de plantes et l&apos;application de fertilisant ont montré que pour la cinquième souche, la population de plantes avait une influence non significative sur le caractères de croissance de floraison de plantes mais la floraison à la durée de moisson et le rendement ha-1 ont significativement diminué (P<0,05) avec la diminution en population des plantes. La sixième souche avait une décroissance significative (P<0,05) en caractère de croissance de hauteur de plante, la floraison à la durée de la moisson, et une augmentation significative (P<0,05) en composantes de rendement de mains de régime et circonférence de doigt avec la diminution en population des plantes. En dépit de l&apos;application de fertilisant à N50K100 et N100K200, il y avait un déclin remarquable pour la sixième souche à cause du basculement et claquement après un vent. Les résultats de nombre des rejets retenus par plante mère et le temps de l&apos;œilletonnage ont indiqué de paramètres de croissance élevés pour la cinquième que la sixième souche à cause de la réduction de la population suite à une carpette élevée, et au fait que les plantes infectées aux charançons et nématodes sont vulnérables au vent. Contrairement à la cinquième souche, la sixième souche a eu tous les paramètres de croissance significativement réduits, avec l&apos; augmentation dans le temps d&apos;œilletonnage. Les meilleurs bénéfices économiques étaient observés à partir de l&apos;œilletonnage matinal et les traitements N50K100 pour toutes les deux souches. Même si le curateur 5G a réduit significativement (P<0,05) les populations de nématodes résultant dans l&apos;indice de necrosis réduit et le traitement à l&apos;insecticide chlordi après le traitement de curateur 5G a effectivement éliminé les charançons de souches, les plantes ne pourront pas effectivement recouvrir leur système des racines dès lors les cormes ont été endommagées au delà du stade de recouvrement. Ainsi, là où l&apos;infestation de charançons et nématodes de banane est apparente, il est critique d&apos;initier l&apos;application d&apos;intervention de contrôle avant la cinquième souche. En plus, les résultats de l&apos;étude indiquent qu&apos;il est meilleur d&apos;établir des nouvelles plantations que de fournir des efforts pour réhabiliter des plantations longuement négligées

The Potential Of Cultural And Chemical Control Practices For Enhancing Productivity Of Banana Ratoons

A study of the effect of plant population, fertiliser application, number of suckers retained per stool and desuckering time on the 5th and 6th banana ratoons was conducted on Kibuzi (AAA-EA) plantation from October 2000 to December 2002. The plantation had earlier (October 1999 to October 2000) received poor management which resulted in high infestation by weevils and nematodes, small bunches and low yields. The study was accomplished in two experiments. In the first experiment, the original spacings of 2.5x2.5m (1,600 plants ha-1), 3x3m (1,111 plants ha-1) and 3.75x3.75m (711 plants ha-1) were maintained in main plots when the plantation was redesigned into a split plot experiment for each original plot with the sub-plots containing N/K fertilisers applied at the rates of 0/0, 50/100 and 100/200-kg ha-1 yr-1 in two splits since these nutrients were limiting. Phosphorus was applied as a blanket cover at 75 kg P ha-1 yr-1. Three suckers were maintained per stool and extra suckers removed using a hand hoe giving a population of 4800, 3,333 and 2133 plants ha-1 at 2.5x2.5m, 3x3m and 3.75x3.75m, respectively. The second experiment originally at a spacing of 3x3 m had a split plot design with 2 and 3 suckers per stool maintained in the main plots and extra suckers removed at time intervals of 1 month, 2 months and 3 months in the sub-plots. Curaterr 5G (carbofuran) and Agro-chlordi (chlorpyrifos/dimethoate mixture) were applied in all the sub-plots at the beginning of both experiments (Oct. 2000) to control banana weevils and nematodes. Results of effect of plant population and fertiliser application showed that in the 5th ratoon, plant population had no significant influence on growth characters of flowering plants but flowering to harvesting duration and yield ha-1 significantly (P < 0.05) decreased with decrease in plant population. The 6th ratoon had a significant (P < 0.05) decrease in growth characters of plant height, flowering to harvesting duration, and a significant (P < 0.05) increase in yield components of hands per bunch and finger girth with decrease in plant population. Despite fertiliser application at N50K100 and N100K200, there was a remarkable decline in the 6th ratoon due to toppling and snapping following windy weather. Results of number of suckers retained per stool and desuckering time indicated higher growth parameters in the 5th than the 6th ratoon due to population reduction owing to high mat, weevil and nematode infected plants being vulnerable to wind damage. Unlike the 5th ratoon, the 6th ratoon had significant (P < 0.05) decrease in all growth parameters with increase in desuckering time. Better economic benefits were observed from early desuckering and N50K100 treatments in both ratoons. Although curaterr 5G significantly (P < 0.05) reduced nematode populations resulting in reduced necrosis index and agro-chlordi insecticide treatment following curaterr 5G treatment effectively eliminated weevils from the ratoons, the plants could not effectively recover their rooting system since the corms had been damaged beyond recovery. Thus, were infestation of banana weevils and nematodes is apparent, it is critical to initiate application of control interventions before the 5th ratoon. Besides, results of the study indicate that its better to establish new plantations rather making efforts to rehabilitate long neglected plantations. Key Words: Desuckering, fertiliser, Musa spp., pests and diseases, plant population RESUME Une étude de l\'effet de la population de plantes, l\'application des engrais, le nombre des rejets retenues par plante mère et le temps de l\'œilletonnage sur la 5eme et 6eme souche était conduite sur plantation de Kibuzi (AAA-EA) à partir d\'Octobre 2000 à Décembre 2002. La plantation avait précédemment (Octobre 1999 à Octobre 2000) reçu une mauvaise gestion résultant d\'une infestation élevée des charançons et nématodes, des petites grappes et faibles rendements. L\'étude était accomplie en deux expériences. Dans la première expérience, les espacement originaux de 2,5 x 2,5 m (1600 plantes ha-1), 3 x 3 m (1111plantes ha-1) et 3,75 x 3,75 m (711 plantes ha-1) étaient maintenus dans les parcelles principales lorsque la plantation était redessinée en parcelle expérimentale divisée pour chaque parcelle originale avec des sous parcelles contenant les fertilisants N/K appliqués aux taux de 0/0, 50/100 et 100/200 kg ha-1 annee-1 en deux fentes parce que ces substances nutritives étaient limitées. Le phosphore était appliqué comme couverture à 75 kg P ha-1 annee-1. Trois rejets étaient maintenus par plante mère et des rejets de surplus enlevés en utilisant une houe manuelle donnant une population de 4800, 3333 et 2133 plantes ha-1 à 2,5 x 2,5 m, 3 x 3 m et 3,75 x 3,75 m respectivement. La seconde expérience originalement à espacement de 3 x 3 m avait un dessin de parcelle divisée avec 2 à 3 rejets par plante mère maintenu dans les parcelles principales et les rejets de surplus enlevés à l\'intervalle de temps de 1 mois, 2 mois et 3 mois dans les sous parcelles. Le curateur 5G (carbofuran) et l\'Agro-chlordi (mélange chlorpyrifos/dimethoate) étaient appliqués dans toutes les sous parcelles au début de toutes les deux expériences (octobre 2000) pour contrôler les charançons et nématodes dans le champs de banane. Les résultats de l\'effet de la population de plantes et l\'application de fertilisant ont montré que pour la cinquième souche, la population de plantes avait une influence non significative sur le caractères de croissance de floraison de plantes mais la floraison à la durée de moisson et le rendement ha-1 ont significativement diminué (

Response of drought tolerant maize inbreds to water stress under nematode infested conditions

Published online: 24 May 2015Maize is the most important cereal food crop is sub-Saharan Africa though yields are below their potential. Among the factors which limit yield, drought stress is one of the most pervasive. The ability of a crop to produce grain under drought (water) stress is governed by many factors including nematodes. The aim of the current study was to determine the response of drought tolerant maize inbreds to nematode attack, understand the interaction between nematode infesta- tion and water stress on maize growth and yield. The study comprised three factors: optimal irrigation against water stress, five nematode treatment condi- tions and ten maize inbreds. Results showed irrigation option 9 genotype interaction to significantly affect growth of the maize crop from 6 weeks after planting. Water stress favoured the reproduction of lesion nematodes ( Pratylenchus zeae ), 50 times more than root knot nematodes ( Meloidogyne incognita ), which showed an increase in most inbreds only under optimal irrigation. Inbreds ACR.SYN-W, La Posta Seq. C7, TZL Comp1C4 and 5057 displayed resistance to P. zeae and M. incognita under water stress, although cobMaize is the most important cereal food crop is sub-Saharan Africa though yields are below their potential. Among the factors which limit yield, drought stress is one of the most pervasive. The ability of a crop to produce grain under drought (water) stress is governed by many factors including nematodes. The aim of the current study was to determine the response of drought tolerant maize inbreds to nematode attack, understand the interaction between nematode infesta- tion and water stress on maize growth and yield. The study comprised three factors: optimal irrigation against water stress, five nematode treatment condi- tions and ten maize inbreds. Results showed irrigation option 9 genotype interaction to significantly affect growth of the maize crop from 6 weeks after planting. Water stress favoured the reproduction of lesion nematodes ( Pratylenchus zeae ), 50 times more than root knot nematodes ( Meloidogyne incognita ), which showed an increase in most inbreds only under optimal irrigation. Inbreds ACR.SYN-W, La Posta Seq. C7, TZL Comp1C4 and 5057 displayed resistance to P. zeae and M. incognita under water stress, although cobMaize is the most important cereal food crop is sub-Saharan Africa though yields are below their potential. Among the factors which limit yield, drought stress is one of the most pervasive. The ability of a crop to produce grain under drought (water) stress is governed by many factors including nematodes. The aim of the current study was to determine the response of drought tolerant maize inbreds to nematode attack, understand the interaction between nematode infesta- tion and water stress on maize growth and yield. The study comprised three factors: optimal irrigation against water stress, five nematode treatment condi- tions and ten maize inbreds. Results showed irrigation option 9 genotype interaction to significantly affect growth of the maize crop from 6 weeks after planting. Water stress favoured the reproduction of lesion nematodes ( Pratylenchus zeae ), 50 times more than root knot nematodes ( Meloidogyne incognita ), which showed an increase in most inbreds only under optimal irrigation. Inbreds ACR.SYN-W, La Posta Seq. C7, TZL Comp1C4 and 5057 displayed resistance to P. zeae and M. incognita under water stress, although co

Early screening of cassava for resistance to root knot nematodes

No Abstract

Early screening of cassava for resistance to rootknot nematodes

Two node cuttings of 18 cassava varieties were planted in 20 cm diameter non-disposable plastic pipes filled with sawdust with the objective of establishing their resistance to root knot nematodes (Meloidogyne spp.). The cassava plants were left to grow for one month after which they were inoculated with 1000 eggs of Meloidogyne spp. Plants were left to grow for another two months after inoculation before assessment. The trial was repeated three times and data pooled for analysis. Greater resistance to root knot nematodes was observed in the cultivars TME 12, Migyera, Nase 10 and TME 5. Cultivars Nase 1, TME 12, 192/0232, Abbey and TME 4 had moderate resistance. These varieties were characterised by low galling index, high plant heights and high fresh root weights. Cultivars TME 14 and P.D.B showed tolerance to root knot nematodes. Varieties, MH 95/0414, 95/SE00087, MM96/0245, 94/SE00036 and MM96/0561, respectively had more than 50% roots galled coupled with low fresh root weights or rotten roots hence, highly susceptible to root knot nematodes. Though varieties 192/0427 and 191/0057 exhibited low galling index, their fresh root weights remained low hence highly susceptible. Meloidogyne spp. populations did not significantly differ across varieties probably because of the short time duration

Awareness of plant parasitic nematodes, and preferred maize varieties, among smallholder farmers in East and Southern Uganda: implications for assessing nematode resistance breeding needs in African maize

In Uganda, nematodes have the potential to cause substantial yield losses, yet it is not known whether farmers have knowledge of the damage these pests cause. A participatory rural appraisal was therefore conducted to assess farmers' awareness of nematodes, and to determine the preferred traits in new maize germplasm. Data were collected from 120 households in two maize-growing districts. Maize roots and soil samples were also collected from farmers' fields, and nematode incidence determined. A small percentage (18.5%) of farmers were familiar with nematodes and the related damage on maize. Pratylenchus zeae occurred at generally higher frequencies than Meloidogyne spp. in the susceptible varieties. The landraces and the cultivar Longe 5 (which reportedly gives the lowest yields) supported high nematode populations. Farmers' most preferred traits were pest and disease resistance, high grain palatability, long storage duration and large kernels. These traits need to be integrated into a breeding programme for nematode resistance in maize

Genetic analysis of resistance to nematodes in inbred maize (Zea mays L.) and maize hybrids

Nematodes cause substantial grain yield loss in susceptible maize (Zea mays L.) cultivars. This study was conducted to estimate general combining ability (GCA), specific combining ability (SCA) and genetic effects associated with nematode resistance in maize. The 30 F1 hybrids generated from a 6 × 6 diallel and two local checks were evaluated in 2009 at three sites in Uganda. A split plot design was used with nematode treatments serving as whole plots and the hybrids as subplots but arranged in an 8 × 4 spatially adjusted alpha-lattice design. The experiment was replicated three times. Results showed GCA to be important for the reduction of P. zeae and Meloidogyne spp. densities and increase of root mass, with a contribution of 72 to 93% of the phenotypic variance. Inbreds MP709 and CML206 had the highest GCA for Pratylenchus zeae resistance, whereas for grain yield, it was CML444, CML312 and CML395 that were outstanding. The SCA influenced plant height and grain yield under nematode infestation, contributing 43 and 58% of the phenotypic variance, respectively. Observed reciprocal differences due to maternal effects also played a role in influencing the grain yield under nematode infestation. Overdominance genetic effects explained the non-additive variance recorded for the plant height, grain yield, number of root lesions, and P. zeae and Meloidogyne spp. densities under nematode infestation. The parents MP709, CML206, 5057, and CML444 contributed most of the dominant genes for the P. zeae resistance in all their crosses. The parent CML444 contributed most of the dominant genes for improved grain yield in all of its crosses. The high GCA effects among some parents support their utility in breeding of widely adapted nematode-resistant cultivars. The dominant genes and SCA effects would favour pedigree and various sib tests to improve grain yield under nematode pressure