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Breeding maize with high contents of zinc, iron and provitamin A (PVA) could be effective in mitigating micronutrient deficiency in developing countries with a high reliance on maize-based diets. Information on the mode of inheritance of zinc, iron, PVA and grain yield (GY) would facilitate the development of varieties with enhanced contents of these nutrients. Twenty-four yellow to orange maize inbred lines and their 96 F1 hybrids generated using North Carolina Design II, were evaluated alongside four checks for two years at two locations in Nigeria. The effects of environment, hybrid and inbred line were significant for GY and contents of zinc, iron and PVA. The GY, and contents of zinc, iron and PVA of the hybrids ranged from 1.49 to 6.05 t ha−1, 22.51 to 33.33 mg kg−1, 20.04 to 29.65 mg kg−1 and 3.55 to 15.28 µg g−1, respectively. Additive gene effects controlled the accumulation of PVA and Fe, whereas both additive and non-additive gene effects controlled the inheritance of Zn and GY. Inbred lines with high general combining ability for GY and single or multiple micronutrients were identified, and could be used to develop hybrids and synthetics that combine high GY with high micronutrient content. Six hybrids combined high GY with high contents of all three micronutrients, and are recommended for further evaluation and possible release. Our study revealed the feasibility of enriching maize with multiple micronutrients without compromising grain yield. [ABSTRACT FROM AUTHOR]

Symbiotic nitrogen fixation in peanut offers an alternative way to reduce chemical nitrogen fertiliz-ation. The objectives of this study were to estimate general combining ability (GCA) and specific combiningability (SCA) effects for traits related to N -fixation and agronomic traits and to identify the best parents2for use in peanut breeding programs aimed at improving nitrogen- ixing ability. Full diallel (F ) crosses of 2 peanut with reciprocals involving five parents were planted in a randomized complete block design with four replications. GCA mean squares were more important than SCA mean squares for plant dry weight, nodule dry weight, leaf color score, seed weight per plant, shelling percentage and harvest index. SCA mean squares were significant for pod weight per plant, seed weight per plant and 100 seed weight. SCA mean squares were more important than GCA mean squares for pod weight per plant, and equally important for seed weight per plant. Reciprocal mean squares were significantly important for 100 seed weight, shelling percentage and harvest index. KKU 72-1, (A3-1-1 (Bc 154) (PI 268770) and 42-G-105 (PI 269 109) were identified as good general combiners for traits related to N -fixation, plant dry weight, nodule dry weight and leaf color score, 2 whereas A3-1-1 (Bc 154) (PI 268 770) and KKU 72-1 were the best parents for 100 seed weight. A3-1-1 (Bc 154) (PI 268 770) was also the best general combiner for shelling percentage and harvest index.

Choice of parental lines is primarily important for the ultimate success of breeding programs, while correlation among traits is also useful information when simultaneous selection for multiple traits is considered. The first objective of this study was to estimate general combining ability (GCA) and specific combining ability (SCA) for fresh and dry weight of nodules, pod yield, seed yield, 100-seed weight, pod number per plant and shelling percentage in the F3 generation of 25 peanut crosses derived from 5x5 North Carolina Mating Design II to identify the best parents for these traits. The second objective was to determine correlation among these traits. The experiment was conducted under field condition at Khon Kaen University'sAgronomy Farm. The 25 crosses and their parents were arranged in a randomized complete block design with 2 replications. GCA mean squares were significant for nodule fresh weight, pod yield, seed yield, 100-seed weight, pod number per plant and shelling percentage, whereas SCA mean squares were not significant for these traits, indicating the importance of additive gene effects governing the inheritance of these traits. PI 269109 had high GCA effects for nodule fresh weight, 100-seed weight, pod number per plant and shelling percentage, and PI 243574 had good combining ability for pod yield and seed yield. KK 60-3 was identified as good general combiner for nodule fresh weight, pod yield, seed yield and 100-seed weight. High and positive phenotypic correlation was found between nodule fresh weight and nodule dry weight. Pod yield,seed yield and 100-seed weight were positively correlated with each other.

A complete diallel cross study of six inbred lines (KKU-BK, KKU-JP, KKU-UB, KKU-JD, KKU-G2 and KKU-N7) of waxy corn was carried out with parents and F1 progeny, to determine the combining ability of starch pasting viscosity characteristics across two environments in Thailand. The relative importance of additive vs. non-additive gene effects was determined. Analysis of variance for all parameters indicated highly significant differences among genotypes and genotype×environment interactions. The general combining ability (GCA) component of variance was significant for most traits, while specific combining ability (SCA) was significant for all of the pasting properties examined, but reciprocal effects were significant except for pasting temperature. Additive gene effects were most important only for peak viscosity; also, the magnitude of GCA variance was more pronounced than SCA variance for this characteristic. However, higher estimates of non-additive genetic variance were noticed for breakdown viscosity, final viscosity, setback viscosity and pasting temperature. Accordingly, the parents KKU-JP and KKU-UB used in this study appear to be suitable parents for use in breeding programs where improved pasting viscosity traits are desired. [ABSTRACT FROM AUTHOR]

Globally potato (Solanum tuberosum L.) is an important food crop which saves millions of hungry people in developing countries. Sometimes over production forces Indian farmers for distress sale due to lack of storage facilities or expensive cold storage. The problem may be solved by developing potato genotypes which can be stored in country storage with minimum loss. Twelve potato genotypes were evaluated for yield and its attributing characters along with storage factors by harvesting potatoes at two different growth phases (75 and 90 days after planting (DAP). Analysis of variance following split plot design revealed presence of significant differences on yield and storage characters. Higher production of marketable tubers was found in K-22 and in Kufri Khyati and MS-1/4353. From total storage study minimum storage loss for different factors was noticed in MS-1/4353 and Kufri Pushkar. These genotypes can be considered in breeding for extended shelf-life under country storage with high yield. Marketable tubers showed maximum direct effect on yield and similarly sprouting loss and desiccation loss revealed maximum direct influence on total tuber loss accompanied by additive gene effect. [ABSTRACT FROM AUTHOR]

A total of 791 animals involved in Thai Native (T), Boer (B), Saanen (S) and their crosses were studied. Fixed effects of sex, birth type, breed group and year-season of birth were found to significantly affect birth weight (BW), weaning weight (WW) and average daily gain (ADG) (P < 0.05). Two statistical models were analyzed in this study. The first model showed that the B breed had higher BW and the S breed had highest WW and ADG than the others (P < 0.05). The T breed had the lowest BW, WW and ADG (P < 0.05) among all breeds and breed crosses. Direct additive and maternal breed effects of B and S breeds from Model 2 had significantly positive values (P < 0.05). It indicated that the B and S purebreds had heavier body weights than the T breed. Direct heterosis, maternal heterosis and recombination effects were not significant. The heterosis estimates of crossbreeding between S and T purebreds tended to yield heavier weaned kids (P > 0.05). Estimated direct and maternal heritabilities were found to be 0.25 and 0.08 for BW, 0.38 and 0.11 for WW and 0.35 and 0.12 for ADG. The direct genetic, maternal genetic and phenotypic correlations among pre-weaning traits were positive with moderate to high values (0.30 to 0.89). The findings provided basic information that farmers and breeders could utilize for an appropriate approach to crossbreeding and monitoring the genetic potential in this herd.

Narrow-leafed lupin ( Lupinus angustifolius L.) is a grain legume well-adapted to sandy acid soils in a Mediterranean climate. Improved metribuzin tolerance in lupin cultivars is considered essential to protect crops from herbicide damage in Australia. This paper reports on the inheritance of metribuzin tolerance in two induced mutants Tanjil-AZ-33 and Tanjil-AZ-55 over the susceptible wild type cv. Tanjil. Both mutants were highly tolerant to 800 g/ha metribuzin with no foliage damage, but cv. Tanjil died and reciprocal F hybrids had intermediate tolerance with foliage damage. The F populations of both crosses, Tanjil-AZ-33 × Tanjil and Tanjil-AZ-55 × Tanjil, had a segregation ratio of 1:2:1 for highly tolerant: damaged:dead plants. Progeny tests (F) of selected F single plants confirmed that highly tolerant F plants were homozygous and damaged F plants were heterozygous. Clearly a single semi-dominant gene conferred metribuzin tolerance in both mutants. An allelism test revealed that the two mutants had two non-allelic tolerance genes with F plants segregating in a 15:1 ratio for survival and death at 800 g/ha metribuzin. The tolerance gene in Tanjil-AZ-33 was designated as Mt3 and the gene in Tanjil-AZ-55 as Mt5. At 4,000 g/ha metribuzin, 1/16 of F plants from the cross between the two mutants had no herbicide damage, suggesting the additive effects of the two tolerance genes, whilst the rest were damaged or dead. Combining these two tolerance genes, Mt3 and Mt5, increased tolerance further by approximately five-fold. [ABSTRACT FROM AUTHOR]