Selection for Iron Efficiency of Soybean in Nutrient‐Solution and Field Tests

Crop Science ◽  
1989 ◽  
Vol 29 (1) ◽  
pp. 86-90 ◽  
Author(s):  
B. W. Diers ◽  
W. R. Fehr
Crop Science ◽  
1986 ◽  
Vol 26 (4) ◽  
pp. 751-752 ◽  
Author(s):  
T. E. Piper ◽  
W. R. Fehr ◽  
B. K. Voss

1968 ◽  
Vol 10 (2) ◽  
pp. 201-207 ◽  
Author(s):  
C. J. M. Hinks ◽  
E. O. Nielsen ◽  
A. Neimann-Sørensen

An investigation of milking ability in three dairy breeds has shown that selection for superior productive performance would contribute little to the improvement of milking time. The heritability of both average rate of flow and milking time was reasonably high in all three breeds, however, and direct selection should result in effective improvements.The problem of slow milking was more acute in the Danish Red breed, in which almost one cow in ten needed more than six minutes to milk out, than in the Black Pied or Danish Jersey breeds.A comparison of the average rate of flow and milking time as criteria of selection for milking ability indicated that both measures were equally effective in the Black Pied and Jersey breeds, but that rate of flow was considerably more (40%) effective than milking time in the Danish Reds. This was largely because the heritability of milking time in this breed was only one-third that of milking rate.It was concluded that the average rate of flow was to be preferred to milking time as a criterion of selection for milking ability in the Danish station testing programme.


1984 ◽  
Vol 64 (1) ◽  
pp. 131-138 ◽  
Author(s):  
J. D. BERDAHL ◽  
R. E. BARKER

Seedling emergence of 30 open-pollinated progeny lines of Russian wild ryegrass (Psathyrostachys juncea (Fisch.) Nevski. Syn: Elymus junceus Fisch.) ranging in seed weight from 2.1 to 4.5 mg/seed was evaluated in laboratory and greenhouse tests and compared to stand establishment capability in the field. Increases in emergence percentage and coleoptile length associated with increased seed weight diminished when seed weights of parents increased beyond 3.0 mg/seed. Emergence in two field environments was correlated with emergence from a 5-cm planting depth in the greenhouse (r = 0.70** and 0.71** for field tests 1 and 2, respectively) and with coleoptile length (r = 0.51** and 0.64**), but not with emergence under laboratory-induced drought stress of −1.1 MPa matric potential (r = −0.05 and 0.13). Experimental error was high for measurements of forage yields in the establishment year (CV = 38% and 36% for field tests 1 and 2, respectively), and resources required to obtain reliable yields would limit testing to a small number of entries. Preliminary screening of a Russian wild ryegrass population for improved seedling vigor could be accomplished by first eliminating plants with small seed size by visual assessment of seed samples. This could then be followed by selection for increased coleoptile length among progeny lines from those plants with medium or large seed.Key words: Russian wild ryegrass, seedling vigor, stand establishment, seed weight, coleoptile length


1989 ◽  
Vol 12 (7) ◽  
pp. 871-880 ◽  
Author(s):  
M. B. Dragonuk ◽  
W. R. Fehr ◽  
H. J. Jessen

1991 ◽  
Vol 18 (2) ◽  
pp. 116-121 ◽  
Author(s):  
A. K. Culbreath ◽  
T. B. Brenneman ◽  
F. M. Shokes

Abstract Fewer stem lesions caused by Cercosporidium personatum (Berk. & Curt.) Deighton developed on peanut (Arachis hypogaea L.) cultivar Southern Runner than on cultivar Florunner in field tests conducted near Tifton, GA, in 1989 and 1990 and near Marianna, FL in 1990. Numbers of lesions per stem and lesions per dm of stem length ranged from 3.1 to 9.5 times higher on Florunner than on Southern Runner in tests where severe leafspot epidemics developed and no foliar fungicides were applied. Seven applications of chlorothalonil at 0.5, 0.63 or 1.26 kg ai/ha via ground sprays and 1.26 kg ai/ha via an underslung boom (Pivot Agricultural Spray System = PASS) allowed few stem lesions to develop on either cultivar compared to non-sprayed plants. Delayed harvest required for Southern Runner resulted in an increase in incidence of stem lesions, but incidence of stem lesions at harvest on Southern Runner still was significantly lower (P ≤ 0.01) than incidence on Florunner at harvest. Differences in number of stem lesions between the two cultivars and among fungicide treatments were reflected in yields. Healthier stem tissue due to fewer stem lesions may be partially responsible for higher yields in Southern Runner than in Florunner grown during severe leafspot epidemics. Incidence of stem lesions caused by C. personatum may be useful as a new parameter to be considered in evaluation and selection for resistance and/or tolerance to C. personatum in peanut.


2021 ◽  
Vol 207 (04) ◽  
pp. 24-33
Author(s):  
Lyudmila Volkova ◽  
Oksana Amunova ◽  
Lyudmila Tiunova

Abstract. Goal. Determination of the effectiveness of early diagnostic methods for resistance to aluminum ions. 15 hybrid populations of F2–F4 spring soft wheat (Triticum aestivum L.), created with the participation of varieties Altayskaya 530, Baganskaya 95, Tyumenskaya 26, Karabalykskaya 98, Gornouralskaya, Lutescens 30, Serebristaya, Jasna were studied. Methods. Laboratory assessment for resistance to aluminum ions in the seedling phase; field tests in two points, differing in pH level and content of mobile aluminum ions (pH1 = 4.3; Al3+ = 5.4 mg/kg of soil; pH2 = 3.8; Al3+ = 211.0 mg/kg of soil); statistical processing of the results. Results. According to the root length index, there were no significant differences between the genotypes, most of the studied samples were characterized as highly resistant (RLI = 80 ... 100 %). The following indicators were characterized by high genotypic indicators: the length of the germ roots, the dry mass of seedlings, the ratio of the root mass to the shoot mass (RSR). The following parameters were characterized by high genotypic conditionality: the length of germinal roots, the dry weight of seedlings, and the ratio of root to shoot weights (RSR). Field stability was assessed by the percentage reduction in signs. The greatest reaction to the conditions of severe edaphic stress was noted in terms of yield (7.1–16.9 % of the norm, depending on the combination), the lowest – in terms of carotenoid content (78.0–111.0 %) and weight of 1000 grains (67.7–89.3 %). No significant correlations were found between RLI, germ root length, and field stability. There was a tendency to increase correlations to average positive or reliable values between laboratory characteristics (length of germ roots, weight of seedlings) and field parameters (size of flag leaves, chlorophyll content, ear productivity elements, yield) during the transition from background 1 to background 2. The ability to redistribute biomass in favor of the aboveground part of plants in the seedling phase (RSR index) had a significant positive effect on productivity elements on both backgrounds. Scientific novelty. Morphophysiological characteristics of seedlings were identified and recommended for selection for resistance to aluminum ions: root length, dry weight of the seedling, RSR index.


2014 ◽  
Vol 61 (6) ◽  
pp. 877-887 ◽  
Author(s):  
Hamid Reza Eshghizadeh ◽  
Amir Hossin Khoshgoftarmanesh ◽  
Mortaza Zahedi

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