scholarly journals Selffertilization in Campanula rotundifolia L. s. 1. group

2015 ◽  
Vol 42 (2) ◽  
pp. 253-264 ◽  
Author(s):  
Halina Bielawska
Keyword(s):  
Pollen Fertility ◽  
Gradual Decrease ◽  
General Tendency ◽  
Seed Setting ◽  
Seed Fertility ◽  
Selfed Seed ◽  
Campanula Rotundifolia ◽  
Tetraploid Level

Artificial selfpollination of six taxa of <i>C. rotundifolia</i> L. group was perfomed. More than 60% of the tetraploid plants and diploid <i>C. rotundifolia</i> s. str. representatives set seeds which germinated in some 42-76%. The seed setting in <i>C. serrata</i> was a little lower and the germination was very poor (0.07%). Only 18% of <i>C. cochleariifolia</i> plants yielded seeds after selfpollination. These seeds failed to germinate. The selfed offspring was viable only in part. Some developmental distur-bances were observed. A general tendency to reduction of height of stems and of the number of flowers per stem was also noted in successive selfed generations. A gradual decrease of pollen fertility was also observed. No tendency to gradual decrease of selfed seed fertility and germination was demonstrated. The factors preventing selffertilization proved to be efficient in <i>C. cochleariifolia</i> and <i>C. serrata</i>, but it seems that in nature they are strong enough even at a tetraploid level.

Chromosome numbers, pollen fertility, and pollen size in Haworthia species and hybrids

1973 ◽  
Vol 51 (10) ◽  
pp. 1753-1759 ◽  
Author(s):  
S. K. Majumdar ◽  
H. P. Riley
Keyword(s):  
Chromosome Numbers ◽  
Pollen Fertility ◽  
Interspecific Hybrids ◽  
Diploid Species ◽  
Pollen Sterility ◽  
Statistical Analyses ◽  
Pollen Size ◽  
Tetraploid Level

Sporophytic chromosome numbers were determined for 216 species, varieties, or hybrids of the genus Haworthia. There were 152 diploids (2n = 14), 10 triploids, 38 tetraploids, 7 pentaploids, 7 hexaploids, and 2 aneuploids. Among the species studied, most of the diploids were highly fertile. The tetraploids were somewhat less so, the triploids were generally less than 50% fertile, and the pentaploids and hexaploids were generally intermediate between the diploids and the triploids. The few diploid interspecific hybrids were less fertile than the diploid species. Each additional set of chromosomes increased the pollen size, and this increment was found to be significant up to the tetraploid level. Statistical analyses of comparisons between pollen size means of the hexaploids and pentaploids, and of the pentaploids and tetraploids were not significant. Pollen sterility is interesting in connection with the problem of speciation in the Aloineae, which is discussed.

ANEUPLOIDS IN THE SOYBEAN, GLYCINE MAX

1974 ◽  
Vol 16 (2) ◽  
pp. 441-447 ◽  
Author(s):  
Reid G. Palmer
Keyword(s):  
Glycine Max ◽  
Chromosome Number ◽  
Plant Height ◽  
Pollen Fertility ◽  
Extra Chromosome ◽  
Glycine Max L ◽  
Tetraploid Level ◽  
Morphological Differences ◽  
Simultaneous Transmission

Aneuploids have been identified among progeny from the homozygous recessive asynaptic soybean (Glycine max (L.) Merr., 2n = 40) mutants T241 and T242. The majority of the progeny (206 of 217) examined were near the tetraploid level and were sterile. The only fertile F1 aneuploid had 36 F2 progeny, which ranged in chromosome number from 41 to 44. Among the F2 progeny, pollen fertility, number of seed per plant, and plant height decreased as chromosome number increased. No morphological differences were observed among the F2 trisomics or between them and fertile diploids. The progeny of 2 of 3 F2 trisomic plants contained plants with 42 chromosomes, suggesting simultaneous transmission of the extra chromosome in both the pollen and the egg.

Utilising Indigenous Knowledge or Crime against Humanity?: A Critical Engagement with the Debate Generated by Alick Macheso’s Use of Manhood to Treat Nhova (Sunken Fontanelle)

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Charles Tembo ◽  
Allan Maganga ◽  
Peterson Dewah
Keyword(s):  
Ethical Issues ◽  
General Tendency ◽  
Ethical Values ◽  
Ethical Considerations ◽  
Lower Back ◽  
African Ethics ◽  
Cultural Grounding ◽  
The Face ◽  
Left And Right ◽  
Points Of View

 This article presents various points of view regarding the treatment of sunken fontanelle by various communities as ignited by the controversial practice of kutara(a practice that involves the father of a child sliding his penis from the lower part of the left and right cheeks to the top of the head, as well as from the lower part of the face to the top of the head, and from the lower back part of the head to the top). The story of Alick Macheso’s use of his manhood to treat nhova (sunken fontanelle) opened a Pandora’s box. The story not only attracted the attention of critics from diverse cultural and ethical backgrounds, but revealed multi-ethnic positions. That is, reactions were steeped in a multiplicity of intellectual, religious and even cultural grounding. Reactions ranged from accusations of backwardness and absurdity, through to medical and Christian orientations toward the treatment of nhova. The overarching idea is that there is a general tendency to dismiss the age-old practice of kutara,coupled with an uncritical celebration of certain positions. The debate that ensued following publication of the story seemed to revolve around ethical considerations. The school of thought that dismisses kutara with disdain regards it as unethical and unimaginable in the present-day world—it is redolent with insinuations of absurdity on the part of those that live and celebrate it. We contend that the raging debate that followed the publication of the story can best be conceptualised within the context of African ethics. We note that kutara has relevance to the spirituality, ethical values, privacy, and protection of children’s rights, among other ethical issues. It is hoped that the article will stir further debate and encourage more research among information practitioners, scholars and researchers into the ethical issues surrounding the treatment of sunken fontanelle in various African communities. It argues for an Afrocentric conceptualisation of phenomena in order to contribute to debates on the renaissance of African cultures, and stresses that it is imperative to harness the life-furthering age-old traditions in African ontological existence.

MORPHOLOGY AND DYNAMICS OF THE LIMANIC BARRIERS ALONG THE BLACK SEA COAST UNDER ACTIVE ANTROPOGENOUS IMPACT

2018 ◽  
Author(s):  
Г. Выхованец ◽  
G. Vyhovanec
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
General Tendency ◽  
Sea Sand ◽  
Black Sea Coast ◽  
Sea Coast

Typical coastal elements of limans and lagoons are barriers, that separate limanic aquatories from a Seas. On limanic shores structure of the Black Sea sand barriers represented three longitudinal landscape “zones”: sea beach (“frontal”), dune-aeolian and limanic (“back of the barrier”). They closely interactive between themselves under influence of lithodynamical exchanges of sediment. General tendency of the barriers dynamics is displacement to Land direction.

Study on floral traits and seed setting in parental lines of hybrid rice during early ahu and kharif seasons

2018 ◽  
Vol 78 (3) ◽  
Author(s):  
Aradhana Phukan ◽  
P. K. Barua ◽  
D. Sarma ◽  
S. D. Deka
Keyword(s):  
Seed Set ◽  
Flag Leaf ◽  
Pollen Dispersal ◽  
Pollen Sterility ◽  
Leaf Length ◽  
Floral Traits ◽  
Opening Angle ◽  
Leaf Angle ◽  
Seed Setting ◽  
Parental Lines

Two CMS lines, IR 58025A and IR 68888A along with their maintainers and two fertility restorers, LuitR and IR 36R, were evaluated for flower and plant characters during early ahu (February-June) and kharif (July-November) seasons. IR 58025A showed longer stigmata and styles, and higher spikelet Length/Breadth (L/B) ratio while IR 68888A showed broader stigmata and wider glume opening angle in both the seasons. IR 68888A also exhibited higher pollen sterility during early ahu. IR 36R was characterized with broad anthers. LuitR showed longer and broader anthers with more pollen than others. Plant height, flag leaf length, flag leaf width and area were higher in IR 36R. Panicle exsertion was complete in pollen parents whereas it was 78-80% in CMS lines. The widest flag leaf angle was found in IR 58025B during early Ahu and in IR 36R during kharif. Kharif season was more favourable for growth of the plants with higher seed set percentage while floral traits of the CMS lines were better expressed in early Ahu. Manipulation of the seeding sequence of the parental lines in early Ahu is warranted for better seed set provided the seed crop escapes heavy premonsoon showers during reproductive stage. IR 68888A/LuitR was a good combination for pollen dispersal and seed setting.

Sign in / Sign up

Export Citation Format

Share Document