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Katrina J.M. Hodgson-Kratky, Olivier M. Stoffyn, and David J. Wolyn

recurrent selection at −0.8 MPa increased germination of sand bluestem ( Andropogon hallii ) nearly 2-fold in vitro ( Springer, 2011 ; Springer et al., 2014 ). In the field, establishment increased 16.4% compared with the base population ( Springer et al

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Tao Dong, Fang-cheng Bi, Yong-hong Huang, Wei-di He, Gui-ming Deng, Hui-jun Gao, Ou Sheng, Chun-yu Li, Qiao-song Yang, Gan-jun Yi, and Chun-hua Hu

using a liquid medium selection system for Agrobacterium- mediated transformation in banana Furenzhi ( Musa spp. AA group) ( Hu et al., 2013 ). The transformants obtained in the liquid coculture phase quickly proliferate in the liquid selection medium

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Givago Coutinho, Rafael Pio, Filipe Bittencourt Machado de Souza, Daniela da Hora Farias, Adriano Teodoro Bruzi, and Paulo Henrique Sales Guimarães

studies on the agronomic performance of quince cultivars cultivated in the tropics, especially in humid subtropical climates, which hiders the selection of cultivars with superior agronomic characteristics and the use of this fruit in regions with a mild

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Shawn A. Mehlenbacher

Turkey and the Caucasus. Most of the world's production is based on selections from local wild populations with different cultivars grown in each zone. Most cultivars are single clones, although some, including a few leading Turkish types (e.g., Tombul

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M. Joseph Stephens, Peter A. Alspach, Ron A. Beatson, Chris Winefield, and Emily J. Buck

commercial traits are needed to be combined into one plant. The use of a selection index approach as described by Falconer and Mackay (1996) for such multiple-trait selection could offer a solution. This approach, designed to give the most rapid improvement

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Yanina Perez Cayo, Steven Sargent, Cecilia do Nascimento Nunes, and Vance Whitaker

overripe. Because of the continuous interest in developing new strawberry genotypes with improved quality traits, additional data on chemical composition and postharvest behavior of new strawberry breeding selections are necessary. These data facilitate the

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Sunita K. Agarwal, David J. Schultz, and Dennis A. Schaff

Most cells have an active turnover of many of their nucleic acids (particularly some types of RNA) which through degradative processes result in the release of adenine, guanine and hypoxanthine. These free purines are converted to their corresponding nucleotides through salvage pathways. Adenine is converted to its nucleotide form AMP by Adenine phosphoribosyltransferase (APRT) which is one of the enzymes associated with the purine salvage pathway. Since all organisms have a de novo pathway for the formation of AMP, APRT is classified as a `salvage enzyme'. The APRT enzyme, in general, does not show a high degree of specificity for the exact structure of adenine and can also act on cytokinins and adenine derivatives like 2,6-diaminopurine, 2-fluoroadenine and 6-methylpurine. The APRT enzyme can utilize adenine analogues as substrate and convert them into their nucleotide forms which are toxic. Plants that lack APRT activity (APRT-plants) survive in the presense of these analogues. The amount of adenine analogue used for selecting APRT-plants is such that it kills all APRT+ (wild type) plants. APRT+ plants survive when grown in the presense of azaserine and alanosine that block de novo synthesis of AMP. APRT-plants transformed with the wild type cloned gene can be selected from a mixture of transformed and non-transformed plants by selecting in the presense of adenine, azaserine and alanosine. The presense of APRT activity can be confirmed by assaying for the APRT enzyme. APRT activity has been detected in many plant species. The presense of a positive forward and backward selection system can thus allow the use of APRT as a selectable marker in plant gene transfer systems.

Open access

W. M. Randle, D. W. Davis, and J. V. Groth

Abstract

Evaluation of the progeny populations from crosses between a resistant sweet corn inbred (Zea mays L.) and 3 susceptible inbreds indicated that the variation for partial resistance to corn leaf rust (Puccinia sorghi Schw.) depended on the parents used. Heritability estimates were high with both additive and dominance gene effects important in character expression. Epistasis was shown to influence rust reaction in at least one cross. The ability to improve partial resistance in 2 sweet corn populations was demonstrated by 3 methods of selection.

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Jorge Rodriguez-A., Wayne B. Sherman, and Paul M. Lyrene

Abstract

A 10-year analysis of the high-density nursery (HDN) in the breeding of low-chilling peach and nectarine [Prunus persica (L.) Batsch] cultivars indicated selection was effective during the first cropping year for chilling requirement, fruit development period, size, color, shape and firmness but not for crop load, which needs to be evaluated at normal spacing over several years. The HDN system effectively has advanced the breeding program by promoting short generation time, reducing labor and space, and allowing for rating of some characters within 2 years from seed.

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Greg T. Browne, Joseph A. Grant, Leigh S. Schmidt, Charles A. Leslie, and Gale H. McGranahan

; Gardena, CA) until they were transplanted as described subsequently. Table 1. Half-sib seed family selections of Chinese wingnut ( Pterocarya stenoptera ) used in the study. Inocula. Inocula of P. cinnamomi and P. citricola were grown on a V8 juice