International Maize and Wheat Improvement Center

About: International Maize and Wheat Improvement Center is a nonprofit organization based out in Texcoco, Mexico. It is known for research contribution in the topics: Population & Agriculture. The organization has 1976 authors who have published 4799 publications receiving 218390 citations.

Leaf Posture, Grain Yield, Growth, Leaf Structure, and Carbon Isotope Discrimination in Wheat

Abstract: The purpose of this study was to examine how differences in leaf angle may affect grain yield of wheat by changes in the relative contribution of yield components or changes in the pattern of crop growth. Leaf structural changes and their influence on plant water status and carbon isotope discrimination were also studied. A collection of pairs of bread wheat (L.) lines (PL) differing in leaf angle were grown under irrigation during two consecutive years at Sonora, Mexico. Erect leaf lines did not have higher yields than droopy leaf lines, but erect lines did have 5 to 16% greater number of kernels per unit of ground area. Droopy lines had a lower number of spikes per unit ground area, a greater number of kernels per spike, and a greater weigh of mature kernels than droopy lines. Therefore, the lack of differences in yield apparently was associated with yield component compensation. Differences between PL in discrimination against C (∆) in mature kernels, relative water content of flag leaves, canopy temperature, leaf area, and degree of leaf tip burning suggested higher transpiration rates (and thus lower water use efficiency) in the erect lines. For example, ∆ in kernels was consistently higher in the erect lines than in the droopy lines. In addition there was a significant (= −0.85, < 0.05) negative correlation between canopy temperature during grain filling and ∆. Grain yield was positively correlated (= 0.50, < 0.05) with ∆ of kernels. Although wheat genotypes with erect leaves did not show conclusive superiority, nevertheless selection for a more erect growth habit may result in increased yield. However, the possible existence of allometric relationships among leaf erectness and smaller leaves, spikes, and stems make progress in increasing yield a complex task.

Physiological performance of synthetic hexaploid wheat-derived populations

Abstract: Wild ancestors of common wheat (Triticum aestivum L.) have been reported to have higher maximum photosynthetic rates than modern wheat cultivars. Synthetic hexaploids, obtained by crossing tetraploid wheat and Aegilops tauschii Coss., have proven useful as a source of resistance or tolerance to biotic and abiotic stresses. This study was conducted to determine whether synthetic hexaploids also could contribute genetic diversity to enhance leaf photosynthetic rate and other physiological traits. Three different populations of BC 2 F 2 , synthetic-derived lines were evaluated at the Agricultural Research ('enter for the Northwest (INIFAP) Experimental Station, near Ciudad Obregon, Sonora, Mexico. Differences in maximum photosynthetic rate were detected among genotypes. Several synthetic-derived lines showed higher photosynthetic rates than their recurrent parent. Staygreen. determined as days between senescence and physiological maturity, of most synthetic-derived lines did not differ from the recurrent parents. Maximum photosynthetic rate was negatively associated with leaf area and positively associated with stomatal and mesophyll conductances, and leaf temperature depression. Mesophyll conductance accounted for 85% of the variation in maximum photosynthetic rate. These results suggest that synthetic-derived wheat can be also a source of genetic diversity for important physiological traits such as enhanced photosynthetic rate.

BrAPI-an application programming interface for plant breeding applications.

Abstract: Motivation: Modern genomic breeding methods rely heavily on very large amounts of phenotyping and genotyping data, presenting new challenges in effective data management and integration. Recently, the size and complexity of datasets have increased significantly, with the result that data are often stored on multiple systems. As analyses of interest increasingly require aggregation of datasets from diverse sources, data exchange between disparate systems becomes a challenge. Results: To facilitate interoperability among breeding applications, we present the public plant Breeding Application Programming Interface (BrAPI). BrAPI is a standardized web service API specification. The development of BrAPI is a collaborative, community-based initiative involving a growing global community of over a hundred participants representing several dozen institutions and companies. Development of such a standard is recognized as critical to a number of important large breeding system initiatives as a foundational technology. The focus of the first version of the API is on providing services for connecting systems and retrieving basic breeding data including germplasm, study, observation, and marker data. A number of BrAPI-enabled applications, termed BrAPPs, have been written, that take advantage of the emerging support of BrAPI by many databases.

Performance of yield and stability of advanced wheat genotypes under heat stress environments of the Indo-Gangetic plains

Abstract: A set of 25 advanced breeding lines and released varieties of wheat (Triticum aestivum L.) developed by different breeding centers in India were assessed for their adaptation in 18 different environments across the Indo-Gangetic plains. The study was aimed at identifying genotype(s) with high yield stability across the environments in general and heat stress environments in particular. Jaipur and Varanasi were hotter than any other locations considered in this study. Considerable intralocation variation in genotypic response pattern was observed over the years and dates of sowing, and this was more conspicuous at Varanasi. Longer crop duration and short grain growth duration at Varanasi were in contrast to shorter crop duration and relatively longer grain growth period that supported better grain growth at Jaipur. The genotype x environment interaction biplots for grain yield revealed that genotypes Raj 3765 and Raj 4027, developed at Jaipur, were more stable across all environments. This was due to their adaptability to high-temperature environments, and hence they are being proposed as promising germplasm sources for late-sown and/or warmer environments. Since the pattern of genotypic response observed at Jaipur was not similar to that observed at Varanasi, it is suggested that a common breeding strategy, if any, should emphasize grain yield stability for breeding for high-temperature tolerance. This can also take care of intralocation variation in genotypic response over the years and dates of sowing at Varanasi.