Interrelation of the Components of Grain Yield in a Cross Between Dwarf and Semidwarf Wheat (Triticum Aestivum L.) Cultivars

Interrelation of the Components of Grain Yield in a Cross Between Dwarf and Semidwarf Wheat (Triticum Aestivum L.) Cultivars PDF Author: Luis E. Medina
Publisher:
ISBN:
Category : Wheat
Languages : en
Pages : 140

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Parents and progeny populations from a cross of 'Stephens'x 'Tibet dwarf' were grown in a spaced-planted experiment to obtain information concerning the nature of inheritance and possible associations between grain yield and the components of yield. Agronomic traits measured on an individual plant basis were: heading date, days to maturity, grain filling period, plant height, biological yield, number of spikes per plant, total length of spikes, spikelets per spike, kernels per spikelet, total kernel number, grain yield, kernel weight, harvest index, and chaff percentage. The nature of gene action was estimated for each trait by comparing broad and narrow sense heritability estimates. Possible associations among traits were determined by phenotypic and genotypic correlations as well as by path coefficient analysis. This latter analysis was based on the genotypic correlations of total grain yield with five other traits. Narrow sense heritability estimates were high for kernel weight, spikelets per spike, heading date, kernels per spikelet, chaff percentage, and total kernel number. Intermediate estimates were found for plant grain yield, spikes per plant, plant height, harvest index, days to maturity and total length of spikes. A low estimate was realized for biological yield. Narrow sense heritability values were higher than broad sense heritability for spikelets per spike, kernel weight, chaff percentage and heading date. These inflated estimates are attributed to sampling errors and/or uneven environmental influence on the various generations. Path coefficient analyses suggested that among the yield components, the number of kernels per spikelet was most closely associated with grain yield, followed by the number of spikelets per plant, the number of spikelets per spike and kernel weight. Low direct associations with grain yield were found for both harvest index and plant height. A moderately high association between harvest index and grain yield was the result of an indirect association via spikelets per spike. As suggested by both narrow sense heritability estimates and path coefficient analysis, selection for number of kernels per spikelet among the F2 populations of the cross of Stephens and Tibet dwarf would result in increased grain yield in succeeding generations. Path coefficient analysis indicated that the direct relation between grain yield and plant height was low, suggesting that short, high yielding plants could be selected within segregating populations resulting from this cross.

Interrelation of the Components of Grain Yield in a Cross Between Dwarf and Semidwarf Wheat (Triticum Aestivum L.) Cultivars

Interrelation of the Components of Grain Yield in a Cross Between Dwarf and Semidwarf Wheat (Triticum Aestivum L.) Cultivars PDF Author: Luis E. Medina
Publisher:
ISBN:
Category : Wheat
Languages : en
Pages : 140

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Book Description
Parents and progeny populations from a cross of 'Stephens'x 'Tibet dwarf' were grown in a spaced-planted experiment to obtain information concerning the nature of inheritance and possible associations between grain yield and the components of yield. Agronomic traits measured on an individual plant basis were: heading date, days to maturity, grain filling period, plant height, biological yield, number of spikes per plant, total length of spikes, spikelets per spike, kernels per spikelet, total kernel number, grain yield, kernel weight, harvest index, and chaff percentage. The nature of gene action was estimated for each trait by comparing broad and narrow sense heritability estimates. Possible associations among traits were determined by phenotypic and genotypic correlations as well as by path coefficient analysis. This latter analysis was based on the genotypic correlations of total grain yield with five other traits. Narrow sense heritability estimates were high for kernel weight, spikelets per spike, heading date, kernels per spikelet, chaff percentage, and total kernel number. Intermediate estimates were found for plant grain yield, spikes per plant, plant height, harvest index, days to maturity and total length of spikes. A low estimate was realized for biological yield. Narrow sense heritability values were higher than broad sense heritability for spikelets per spike, kernel weight, chaff percentage and heading date. These inflated estimates are attributed to sampling errors and/or uneven environmental influence on the various generations. Path coefficient analyses suggested that among the yield components, the number of kernels per spikelet was most closely associated with grain yield, followed by the number of spikelets per plant, the number of spikelets per spike and kernel weight. Low direct associations with grain yield were found for both harvest index and plant height. A moderately high association between harvest index and grain yield was the result of an indirect association via spikelets per spike. As suggested by both narrow sense heritability estimates and path coefficient analysis, selection for number of kernels per spikelet among the F2 populations of the cross of Stephens and Tibet dwarf would result in increased grain yield in succeeding generations. Path coefficient analysis indicated that the direct relation between grain yield and plant height was low, suggesting that short, high yielding plants could be selected within segregating populations resulting from this cross.

Nuclear Science Abstracts

Nuclear Science Abstracts PDF Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 1202

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The Journal of the Australian Institute of Agricultural Science

The Journal of the Australian Institute of Agricultural Science PDF Author: Australian Institute of Agricultural Science
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 570

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Australian Journal of Experimental Agriculture

Australian Journal of Experimental Agriculture PDF Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 480

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Bibliography of Agriculture with Subject Index

Bibliography of Agriculture with Subject Index PDF Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 1238

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Bibliography of Agriculture

Bibliography of Agriculture PDF Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 1732

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Wheat

Wheat PDF Author: Y. P. S. Bajaj
Publisher: Springer Science & Business Media
ISBN: 3662109336
Category : Technology & Engineering
Languages : en
Pages : 701

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Book Description
Wheat, which is the second most important cereal crop in the world, is being grown in a wide range of climates over an area of about 228 945 thou sand ha with a production of about 535 842 MT in the world. Bread wheat (Triticum aestivum L. ) accounts for 80% of the wheat consumption, howe ver, it is attacked by a large number of pests and pathogens; rusts and smuts cause enormous damage to the crop and reduce the yield drastically in some areas. The major breeding objectives for wheat include grain yield, earliness, resistance to lodging and diseases, spikelet fertility, cold tolerance, leaf duration and net assimilation rate, fertilizer utilization, coleoptile length, nutritional value, organoleptic qualities, and the improvement of charac ters such as color and milling yield. The breeding of wheat by traditional methods has been practiced for centuries, however, it has only now come to a stage where these methods are insufficient to make any further breakthrough or to cope with the world's demand. Although numerous varieties are released every year around the world, they do not last long, and long-term objectives cannot be realized unless more genetic variability is generated. Moreover, the intro duction of exotic genetic stocks and their cultivation over large areas results in the depletion and loss of the native germplasm pool.

Agronomy News

Agronomy News PDF Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 710

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Book Description
Sept.-Oct. issue includes list of theses and dissertations for U.S. and Canadian graduate degrees granted in crop science, soil science, and agronomic science during the previous academic year.

Duration and Rate of the Grain Filling Period and Subsequent Grain Yield in Crosses Between Facultative and Winter Wheat Cultivars (Triticum Aestivum L. Em Thell)

Duration and Rate of the Grain Filling Period and Subsequent Grain Yield in Crosses Between Facultative and Winter Wheat Cultivars (Triticum Aestivum L. Em Thell) PDF Author: Beiquan Mou
Publisher:
ISBN:
Category : Wheat
Languages : en
Pages : 138

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Book Description
Concerns about the genetic control and environmental influence of various stages of development including the grain filling period, and the relationship between early maturity and grain yield prompted this study. The experimental material consisted of two facultative and two winter wheat cultivars. A dial!el cross, excluding reciprocals, was also developed to provide an Fl generation. Information was collected for 14 traits and subjected to statistical analyses. Genetic differences among varieties were found for time of heading, flowering and physiological maturity, duration and rate of the grain filling period, grain yield and yield components. The facultative types, AI Feng 2 and Selection CB 83-52, showed earlier heading, flowering and physiological maturity, longer lag period (period between heading and flowering), and longer duration and lower rate of grain filling, resulting in lower grain yield. The winter cultivars, Stephens and Yamhill Dwarf, in contrast had later heading, flowering and maturity, shorter lag period, and shorter duration and higher rate of grain filling, giving higher grain yield. For the developmental stages after heading, larger differences were observed in the lag period while differences in duration of grain filling period were relatively small among the cultivars. Depending on the specific Fl population, there was a tendency toward dominance for early heading, a range from no to complete dominance for early flowering and no dominance for physiological maturity. Long duration and fast rate of grain filling were generally dominant. Grain yield was positively associated with the number of days to heading, flowering and physiological maturity. Also positive associations of grain yield were obtained with tiller number, kernel weight, grain weight per spike, biological yield and rate of grain filling. Negative associations of grain yield were noted with lag period and duration of grain filling period. No clear associations between physiological maturity and the yield components were found. Grain filling duration showed no association with yield components while grain filling rate exhibited positive association with tiller number and kernel weight. There was negative association between duration and rate of grain filling period. According to heading responses from different planting dates, Stephens and Yamhill Dwarf had high sensitivity while Selection CB 83- 52 and AI Feng 2 showed low sensitivity to vernalization. Genotype X environment interaction was observed with each cultivar responding differently for several traits depending on the planting dates.

Genetic Diversity in Plants

Genetic Diversity in Plants PDF Author: Amir Muhammed
Publisher: Springer Science & Business Media
ISBN: 1468428861
Category : Medical
Languages : en
Pages : 493

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Book Description
For the last eighteen years we have been deeply involved in a cooperative effort with our Latin American colleagues in genetics, biochemistry, physiology, and molecular biology. We have been in close contact with scientists in a number of centers and have helped to organize symposia, workshops, and so forth, in an effort to accelerate their development and make their substantial work known. These symposia in Latin America have been quite successful. The fifteenth will take place in Brasilia in 1977. At the request of colleagues, we are in the process of developing a similar series in Asia. The first very successful symposium was held in Calcutta in 1973. We were most pleased when Dr. Amir Muhammed, Vice Chancellor of the University of Agriculture, Lyallpur suggested that we hold a symposium on a topic of great importance to Pakistan, Genetic Control of Diversity in Plants, under the auspices of the University of Agriculture. It is our hope that this symposium will be followed by additional ones in Pakistan as well as in other countries in the Far East. Leadership is quickly developing in the hands of outstanding scientists in these countries, and we appreciate the opportunity to cooperate with them. We are especially grateful to the Natiohal Science Foundation for makingPL- 480 funds available which made this symposium possible.