Showing papers in "Journal of Genetics in 1963"
TL;DR: In a large random mating population segregating for a pair of allelomorphics with full dominance, the condition that neither allelomorph should disappear is that the arithmetic mean of the fitnesses of recessives in different generations should exceed unity, their geometric mean fall below it.
Abstract: In a large random mating population segregating for a pair of allelomorphs with full dominance, the condition that neither allelomorph should disappear is that the arithmetic mean of the fitnesses of recessives in different generations should exceed unity, their geometric mean fall below it.
438 citations
TL;DR: Investigations were started in 1959 in Andhra Pradesh, India to find out the frequency of different types of consanguineous marriages among the inpatients of King George Hospital, their parents, their children and the parents of school children of two schools in Visakhapatnam and one school in Waltair.
Abstract: 1. Investigations were started in 1959 in Andhra Pradesh, India, to find out the frequency of different types of consanguineous marriages among the inpatients of King George Hospital in Visakhapatnam, their parents, their children and the parents of school children of two schools in Visakhapatnam and one school in Waltair.
96 citations
TL;DR: Polymorphism may be due to the fact that the fitness of a phenotype diminishes as its numbers increase, and it is shown that under natural conditions instability is unlikely.
Abstract: Polymorphism may be due to the fact that the fitness of a phenotype diminishes as its numbers increase. The stability of the equilibrium is discussed, and it is shown that under natural conditions instability is unlikely.
46 citations
TL;DR: Two partially dominant genes governing resistance to blackarm (Xanthomonas malvacearum) have been transferred from Gossypium herbaceum to Sakel,G.
Abstract: Two partially dominant genes governing resistance to blackarm (Xanthomonas malvacearum) have been transferred fromGossypium herbaceum (n=13,A
1 genome) to Sakel,G. barbadense (n=26, (AD)2 genome). The stronger of these genes has been given the symbolB
9; no symbol has been allocated to the weaker gene because gene homology tests have not been made between this and the other known genes.
26 citations
TL;DR: The Lefts give 20·9 percent excess yield of nuts over their counterpart, although it is based on a non-inherited character, and that is quite inexplicable, and it is not known whether the increase in the number of nuts of the Lefts is associated with a proportionate increase inThe weight of copra.
Abstract: Further data confirm that the direction of leaf spirals inCocos nucifera is non-inherited. In all probability it is also not genetically determined. Fresh data on the frequency of Lefts and Rights from India as well as 27 other countries are reported. A slight excess of Lefts is noticed in most populations, but on the totals, the two groups do not differ significantly. However, in the case of a few countries, abnormal figures were received which show significant differences between the Lefts and Rights. The Lefts give 20·9 percent excess yield of nuts over their counterpart, although it is based on a non-inherited character, and that is quite inexplicable. Among diseased palms also the difference is in the positive direction, but not significant by itself. The number of the leaves of the Lefts is slightly greater, and this may account, in part, for the increased yield of nuts of the Lefts. It is not known whether the increase in the number of nuts of the Lefts is associated with a proportionate increase in the weight of copra.
23 citations
TL;DR: The family Verbenaceae, a constituent of the bicarpellate complex, is characterised by a large number of genera occurring mainly in the tropics, and provides ideal material for cytologists who are interested in working out the basis of origin of different chromosome number% and interrelationships and affinities between genera and species as far as can be interpreted from cytological data.
Abstract: The family Verbenaceae, a constituent of the bicarpellate complex, is characterised by a large number of genera occurring mainly in the tropics. In the pia~.ns of Bengal alone, fortyeight species occur as wild, and a large number of them are cultivated as well. Taxonomic interest is provided by the family, its variety of forms ranging from herbaceous to woody. One of the most commonly occurring shrubby forms is exhibited by the species of Clerodendron. Further, in C. infortu,ialum Gaertn., the most frequent species of this genus, phenotypic differences between individuals are commonly seen. Cytological reports in this genus show a wide range of chromosome numbers Ii'om 24 to I84. The possibility of existence of individuals with different chromosome numbers in the same species has been indicated by tbe discrepant reports of Nishiyama and Kondo (t942) and Bowden (1945~, one reporting fortysix and the other fortyeigbt chrm=osomes in the somatic cells respectively. In Inaia a large number of species of this genus still remains unexplored and no detailed Cytological work has yet been done on C. it~ortunatum with its wide range of phenotyi~es. In addition to CIerodendron~ cytological interest is prdvlded by other genera in the fact that a wide range of chromosome nflmbers has been found in different genera of this family, starting fi'om n=5 in, Verbena to even n=23 in Clerodendron. Leaving aside the occurrence of polyploidy in the same species (Sugiura, 1936b) arieuploid variations at an intraspecific level are recorded in Call@ar~a japonica by Sugiura (1936b) and Patermann (1938) and \"s (Schnack, 1947; Tjlo, 1948; Singh, 1951) too. I.nterspecific aneuploidy, is also common in the genera Lippia and Lantana (Sharma and Mukhe@e, unpublished; Natarajan and Ahuja, .1957; etc.). All these facts taken together suggest that the family provides ideal material for cytologists who are interested in working out the basis of origin of different chromosome number% and interrelationships and affinities between genera and species as far as can be interpreted from cytological data. With these ends in view the present investigation was undertaken on thirtyfive different species and varieties with special reference to the genus Clerodend, vn.
19 citations
TL;DR: The distribution of tooth numbers on leaves of Nyctanthes arbor-tristis Linn was approximately unimodal on five trees, the modal number being zero, and bimodalon three, the modes being zero and six to ten.
Abstract: The distribution of tooth numbers on leaves ofNyctanthes arbor-tristis Linn. was approximately unimodal on five trees, the modal number being zero, and bimodal on three, the modes being zero and six to ten. The modal number of petals of flowers on 17 trees of this species was six in 18 trees and five in one. The variances as well as the means of the trees differed significantly. During a flowering season of four months the mean petal number on three trees fell by 2% to 5% and then rose again. The variances rose steadily and were from 20% to 40% greater at the end of the season than the beginning. Similar increases in variance of petal number were observed in two plants of a winter-flowering variety ofJasminum multiflorum over two months, and two plants of a summer-flowering variety of the same species over four months. It may be said that canalization broke down during the season in each case.
19 citations
TL;DR: A brief review of heterostylic species of Rubiaceae has been made and biometrical data pertaining to the pollen grains of the long and short styled plants has been analysed.
Abstract: A brief review of heterostylic species of Rubiaceae has been made. Counts of natural populations of the distylicOldenlandia umbellata have been made from six localities. Out of a total of 1,894 plants counted, there were 1,093 long styled plants and 801 short styled plants. Long and shortstyled plants are self incompatible. Seeds are set only in legitimate crosses. Biometrical data pertaining to the pollen grains of the long and short styled plants has been analysed. Short styled pollen grains are larger than long styled. Measurements of styles, anthers, and stigma papillae are also given.
17 citations
TL;DR: General combining ability and sex linked effects were highly significant for weights but not for litter size, and there was no evidence of an interaction between maternal effects and mating systems.
Abstract: These data are in general agreement with those found with other mammalian species. Maternal effects for weights were demonstrated with these data and have also been reported in other work with mice and rats; however, maternal effects have been lacking in studies with swine.
15 citations
TL;DR: Whenqn is a parameter of a population in generationn,qn+1 is often a simple function of qn, and if so,n is an automorphic function ofqn, which permits the expression ofn as an infinite series which often converges quickly, and allows numerical calculation.
Abstract: Whenqn is a parameter of a population in generationn,qn+1 is often a simple function ofqn. If so,n is an automorphic function ofqn. A simple transformation ofqn permits the expression ofn as an infinite series which often converges quickly, and allows numerical calculation. It is sometimes possible to obtain a very close approximation to the value ofn in terms of logarithms. Examples are given.
9 citations
TL;DR: It seems unwise to ignore sex-linkage in quantitative inheritance without further testing, and it is recommended that the evidence is by no means all in favour of the negligible sex- linkage alternative.
Abstract: The belief that sex-linkage is unimportant in quantitative inheritance is not based on evidence.
TL;DR: Observations suggest that several genes may be involved in controlling the expression of the phenotype in men with hypertrichosis of the helix.
Abstract: An examination of the ears of 871 Oriya males in Orissa, 152 Bengali males in Calcutta, and 413 Sinhalese males in Ceylon showed that the percentage of men with hypertrichosis of the helix is 14·5, 15·8, and 37·04 respectively. The incidence among those aged 20 years or less is 5·44 per cent in Orissa and 7·7 per cent in Ceylon. None among the 33 Bengalis aged 23 years or less had hairy pinnae. The percentage of men with hairy pinnae is 58·3 in Orissa and 59·8 in Ceylon among those aged 45 years or more, and the increase over the age of 44 years is significant in Orissa, and nearly so in Ceylon. In the Bengali data, the increase is significant over the age of 29 years. These observations suggest that several genes may be involved in controlling the expression of the phenotype.
TL;DR: Neither mean chaeta number nor mean wing length was affected by inbreeding, and phenotypic variance tended to increase with increase in the level of inbreeding up to F=.500 and beyond this, it tended to decline.
Abstract: Eight populations ofDrosophila melanogaster were raised to varying levels of inbreeding:F=0.000, 0.250, 0.375, 0.500, 0.672, 0.734, 0.785 and 0.908. Estimates of covariances between full sibs and between half sibs for bristle number and wing length were made in each of these populations. The estimates for bristle number showed a linear rise with increase inF values. Statistically, the rise was not significant. The estimate for wing length did not show any specific trend in relation to the level of inbreeding. The results are discussed in the light of theoretical expectations.
TL;DR: The present author studied an analogous dependence of crY, on P (given A and a) with reference to g, substantially the same as ~[~ere.
Abstract: ]In a previous paper (Binet and iV[orris, 1962), ,he dependence of crY, on P (given A and a) was considered. In the framework ~ of tha~ paper, the present author studied an analogous probIem'with reference to ~g. The frame of reference is substantially the same as ~[~ere. Some additional definitions extend the model so as to fit into it the required additional concepts. The notation is slightly altered so as to simplify the necessary algebraic manipulation.
TL;DR: The mode of inheritance of anthocyanin pigmentation in the leaf blade has been studied by making inter-crosses between the three pigmented types and between these pigmented and several green leaf blade types, showing the role of each gene and its relationship with others is presented to explain this inheritance.
Abstract: Three leaf blade pigment patternsviz., purple (Strain CP.12), purple wash (Strain CH.17) and faint purple wash (Strain CH.17mutant) have been described. The mode of inheritance of anthocyanin pigmentation in the leaf blade has been studied by making inter-crosses between the three pigmented types and between these pigmented and several green leaf blade types. A six factor hypothesis showing the role of each gene and its relationship with others is presented to explain this inheritance. TheF
2 segregation of 13:3, 55:9 and 229:27 of green: purple leaf, obtained in crosses between CP.12 × HS.22, CP.12 × T.1029/2 or CP.12 × T.786 and CP.12 × T.136 respectively is due to two, three and four gene differences respectively between the parents crossed; one of these genes is an inhibitory factor which suppresses the expression of purple pigment. The 9:7 and 27:37 ratios of purple wash: green in crosses between CH.17 and green leaf blade varieties are due to the interaction of two and three complementary genes respectively. TheF
2 segregation of 39 purple wash:12 purple:13 green obtained from the cross CP.12 × CH.17 (purple × purple wash) is shown to be due to interaction of complementary factors and presence of an inhibitory geneIlp, the latter being epistatic over geneLp for purple colour. The four factor segregation of 117PW: 36P: 48FPW: 55G in the cross CP.12 × CH.17mutant, is shown to be due to interaction of four complementary genes one of which is a lower alleleLd′ and the other an inhibitory factorIlp.
The monogenic segregation obtained from the cross CH.17 × CH.17mutant is shown to be due to a single factor differenceLd-Ld′. The occurrence of purple wash leaf blade phenotype along with the faint purple wash and green leaf blade phenotypes in theF
2 of the cross AC.16 × CH.17mutant (G × FPW) has been explained as being due to the presence of the higher alleleLd in AC.16 as against the lower alleleLd′ present in CH.17mutant. Some of the anomalous ratios like 3 green: 1 purple, 10 green: 1 purple and 8.3 green: 1 purple reported by previous workers have been explained on the basis of the six factor hypothesis.
TL;DR: It is argued that the present method for estimating polygenic mutation rate is on the same basis as the conventional method for obtaining major gene mutation rate.
Abstract: General equations have been derived for estimating polygenic mutation rate per locus per unit dose. It is argued that the present method for estimating polygenic mutation rate is on the same basis as the conventional method for obtaining major gene mutation rate. An example has been given in order to show how to use the equations for calculating polygenic mutation rate.
TL;DR: The number of gametes tested in a series of experiments should be inversely as the square root of the expected mutation frequency in order to get the best estimate of the difference of two mutation rates.
Abstract: In order to get the best assurance that two mutation frequencies differ, or the best estimate of their ratio, the number of gametes tested in a series of experiments should be inversely as the square root of the expected mutation frequency. In order to get the best estimate of the difference of two mutation rates it should be directly as the square root of this frequency.
TL;DR: The wild Mexican potato, Solanum demissum, is a short-day type for tuber formation and under the long days of an English summer produces few tubers or none, while top-grafted with scions of S. tuberosum varieties tolerant of long days for tubers produces a much higher yield of tubers than when not grafted.
Abstract: 1. The wild Mexican potato,Solanum demissum, is a short-day type for tuber formation and under the long days of an English summer produces few tubers or none.
TL;DR: The mathematical theory of natural and artificial selection is likely to become as complicated as that of gravitational astronomy, but a few problems are fairly simple; the effects of mutation are neglected in this article.
Abstract: The mathematical theory of natural and artificial selection is likely to become as complicated as that of gravitational astronomy, I~towever a few problems are fairly simple. The deterministic theory of artificial, or complete, select[on based on the elimination of one phenotype is simple when the phenotypes are genetically determined by a single factor, or a pair of allelomorphic genes, in a very large population. A fully or partially dominant gent can be eliminated in one generation. The effects of mutation are neglected in this article. In a moderately large population they must be treated stochastically. In a very large one they can be treated deterministically, the number of mutants in each generation becoming nearly constant. Punnett (19t7) gage the expression for the rate at which recessives are eliminated when they are prevented from breeding in a random mating population segregating for a pair of autosomal allelomorphs. I f both homozygotes are eIiminated segregation cont[nues indefi~litely. Ifheterozygotes are eliminated then if the ratio of AA to a a in gmleration