scholarly journals Inbreeding and Gene Action in Butternut Squash (Cucurbita moschata) Seed Starch Content

2014 ◽  
Vol 67 (1) ◽  
pp. 7169-7175 ◽  
Author(s):  
Sanin Ortiz Grisales ◽  
Lucy Viviana Bastidas Burbano ◽  
Ginna Alejandra Ordoñez Narváez ◽  
Magda Piedad Valdés Restrepo ◽  
Diosdado Baena García ◽  
...  

The effect of inbreeding and gene action on butternut squash (Cucurbita moschata Duch.) seed production and seed starch content was evaluated at two locations in the department of Valle del Cauca, Colombia, using six accessions (S0) and their inbred lines S1 and S2. Significant differences were found between the accessions and inbred lines, but not between localities. The seed production and seed starch content showed no significant effects of inbreeding depression. An additive-type gene action predominated, suggesting that recurrent selection could be the best strategy to increase the frequencies of genes promoting seed production and seed starch content.

Author(s):  
R. Narasimhulu ◽  
N. V. Naidu ◽  
K. H.P. Reddy

Five crosses were evaluated to study the extent of heterosis and inbreeding depression for yield and its attributing traits in greengram. Heterosis over mid parent, better parent and standard variety was significant for pods/plant and seed yield/plant. The crosses exhibiting high heterosis also expressed high inbreeding depression for pods/plant, pods/cluster and seed yield/plant. Heterosis coupled with inbreeding depression revealed the predominance of non-additive gene action for most of the characters studied. Owing to its autogamous genetic architecture and biological constrains of the crop the heterosis could be exploited only by isolating the desirable segregants for yield attributes adopting bi-parental or recurrent selection in early segregating generations followed by single plant selection in subsequent generations.


2004 ◽  
Vol 61 (2) ◽  
pp. 224-227 ◽  
Author(s):  
Antonio Ismael Inácio Cardoso

The strategy for breeding F1 hybrid squash is to develop parental lines through self-pollination. However, it increases plant mean homozygosis, which is not the natural genetic state of a cross-pollinated species, and can cause "inbreeding depression". The objective of this work was to evaluate this depression with sucessive generations of self-pollination (without selection) in Cucurbita moschata, cv. Piramoita. Populations were obtained from lines with one to four generations of self-pollination (obtained by the SSD method), from the original cv. Piramoita (population S0). Randomized blocks were used with five treatments (different generations of self-pollination - S0 to S4), six replicates and five plants per plot. Regression analysis was made by the Wright inbreeding coefficient (F) to measure the homozygosis level effect on vigor loss. There was a linear reduction of mean weight and fruit length, seed production (number and weight) per fruit with the increase of the homozygosis level; however inbreeding did not affect seed quality (weight of 100 seeds and germination).


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4133
Author(s):  
Henrique José Camargo Senhorinho ◽  
Ronald José Barth Pinto ◽  
Carlos Alberto Scapim ◽  
Klayton Flávio Milani ◽  
Thiago Hideyo Nihei

<p>The objective of this study was to evaluate the combining ability and inbreeding depression of commercial maize hybrids for agricultural traits. Twenty-two commercial maize hybrids, 96 F1 crosses from a partial diallel scheme, 22 S1 populations and 4 controls were evaluated in a 12x12 simples square lattice experimental setup, totaling 144 treatments, in the municipality of Sabáudia (PR), Brazil, for harvests from 2011/2012 and 2012/2013. Three traits were evaluated: grain yield, plant height and ear height. The Griffing method (1956) was applied for the evaluation of the general combining ability (GCA) and specific combining ability (SCA). The 30B39, 30K64 and 30B30 hybrids showed increased yield, 30F53 and P1630 showed reduced plant height and AG9040 and AG7010 showed reduced ear height. These hybrids can be recommended for the extraction of inbred lines and formation of composites followed by intrapopulation selection. The combinations 30B39 x AG8088, 30B39 x AG9045 and P1630 x AG8021 showed desirable SCA effects for grain yield, plant height and ear height and are recommended for use in reciprocal recurrent selection programs. High magnitudes of inbreeding depression were verified for yield and lower values for inbreeding depression for plant and ear heights. Thus, strategies are recommended for interpopulation breeding accompanied by inbred lines extraction.</p>


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4133
Author(s):  
Henrique José Camargo Senhorinho ◽  
Ronald José Barth Pinto ◽  
Carlos Alberto Scapim ◽  
Klayton Flávio Milani ◽  
Thiago Hideyo Nihei

The objective of this study was to evaluate the combining ability and inbreeding depression of commercial maize hybrids for agricultural traits. Twenty-two commercial maize hybrids, 96 F1 crosses from a partial diallel scheme, 22 S1 populations and 4 controls were evaluated in a 12x12 simples square lattice experimental setup, totaling 144 treatments, in the municipality of Sabáudia (PR), Brazil, for harvests from 2011/2012 and 2012/2013. Three traits were evaluated: grain yield, plant height and ear height. The Griffing method (1956) was applied for the evaluation of the general combining ability (GCA) and specific combining ability (SCA). The 30B39, 30K64 and 30B30 hybrids showed increased yield, 30F53 and P1630 showed reduced plant height and AG9040 and AG7010 showed reduced ear height. These hybrids can be recommended for the extraction of inbred lines and formation of composites followed by intrapopulation selection. The combinations 30B39 x AG8088, 30B39 x AG9045 and P1630 x AG8021 showed desirable SCA effects for grain yield, plant height and ear height and are recommended for use in reciprocal recurrent selection programs. High magnitudes of inbreeding depression were verified for yield and lower values for inbreeding depression for plant and ear heights. Thus, strategies are recommended for interpopulation breeding accompanied by inbred lines extraction.


2001 ◽  
Vol 126 (5) ◽  
pp. 575-578 ◽  
Author(s):  
Eduardo Villanueva-Mosqueda ◽  
Michael. J. Havey

Development of two-way onion (Allium cepa L.) hybrids is difficult due to poor seed yields on inbred female parents. Seed yield of onion is affected by inbreeding depression and the seed-production environment. A standard diallel was used to estimate combining abilities for seed yield among seven inbred onion lines. Males and hybrids differed significantly (P < 0.05) for seed yields. Combinations of relatively high-by-high seed-yielding inbred parents were not always the best combinations; combinations of medium-by-medium or medium-by-high seed yielders also produced good F1 seed yielders. For the seven inbred lines, significant correlations (P < 0.05) were observed between mean seed yield per bulb and scape height. Parent-offspring regressions revealed no significant relationship between seed yields of randomly selected, open-pollinated bulbs and their S1 families. Results indicate that relative seed yields of individual bulbs after self-pollination cannot be used to predict seed yields of progeny families. However, the seed yield of inbred lines of onion may reflect the potential seed yield of F1 male-sterile lines.


2012 ◽  
Vol 12 (4) ◽  
pp. 269-276
Author(s):  
Inocencio Junior de Oliveira ◽  
Maurício Dutra Zanotto ◽  
Milton Krieger ◽  
Roland Vencovsky

The purpose of this study was to investigate inbreeding depression (DE) in castor bean. From a population derived from the Guarani cultivar, 60 mother plants were sampled. Three types of progenies were obtained from each one: from self-pollination (AU), from crosses (CR) and from open pollination (PL). Grain yield of the progenies was evaluated in two locations. There was a strong interaction of progenies x locations, which led to obtaining estimates within each location. Broad variation was observed in inbreeding depression, with mean values of 6.7% and 13.4%, comparing AU progenies with PL progenies. It was observed that the population has high potential for selecting promising inbred lines. The frequency of mother plants generating progenies with simultaneous high general combination capacity and low inbreeding depression was low. Recurrent selection will increase the occurrence of parent plants associating these two properties, which is necessary for obtaining superior synthetic varieties.


2018 ◽  
Vol 24 (2) ◽  
pp. 55-66
Author(s):  
Rokhana Faizah ◽  
Sri Wening ◽  
Hernawan Yuli Rahmadi ◽  
Abdul Razak Purba

Inbreeding is a common method used to reproduce candidate mother plant from selected parental lines for commercial seeds in Reciprocal Recurrent Selection (RRS) oil palm breeding program. However this practice may increased homozigosity level of selected population. This study concerned the level of homozygosity of SP540T fourth generations and Dura Deli Dolok Sinumbah fifth generations (3 crosses respectively) and their correlation with inbreeding depression symptoms. Polymerase Chain Reaction-Simple Sequence Repeat (PCR-SSR) with 16 markers developed for oil palm was used to analyze 327 samples. The result shows that the levels of homozigosity of SP540T fourth selfing generation were ranged between 0.44-0.84 or 0.61 in average. While the levels of homozygosity of Dura Deli fifth selfing generations were ranged between 0.60-0.93 or 0.78 in average. The homozygosity level in Dura Deli was 1.27% higher than SP540T populations. Correlation analysis showed that the higher the level of homozygosity, the higher of the inbreeding symptoms 2 observed (R =0.95).


Author(s):  
Andreea Daniela ONA ◽  
Ioan HAȘ ◽  
Ivan ILARIE ◽  
Voichița HAȘ ◽  
Nicolae TRITEAN ◽  
...  

In the last 40 years, pre-breeding works induced, in more and more centers of maize breeding, full-sib reciprocal recurrent selection programmes to identify some heterotic pairs which can be sources for obtaining performance inbred lines. The aim is to identify the heterotic pairs with the best results according to the yield potential of maize, the breaking and falling resistance, and the grains moisture at the harvesting time. The creation programme of A and B composite population started at ARDS Turda in 1985. Inside of A composite came the next inbred lines: B73, A632, M117, TC209, T291, being from the B SSS heterotic group, and inside of B composite came the inbred lines Mo17, C103, TC 208, T248, W633, appreciated by us or being related to Lancaster Sure Crop heterotic group. The experimentation was done in two orientation comparative cultures, each one with 49 variants, in 4 repetitions; the comparative culture was a balanced quadratic grid of 7x7 type. From each culture were chosen the first six variants, which were evaluated according to the next characters: production potential, breaking and falling resistance, grains moisture at harvest. The presented results are a part from the second cycle of full-sib reciprocal recurrent selection. Test crosses and self-pollinations were made on plants from the two composites which had two cobs; on the first cob from A Composite realised the cross with the corresponding plant from the B Composite, and from the plant panicle of the B Composite was collected pollen to pollinate the chosen plant from the A Composite. At the both plants from the crossing, the second cob was self-pollinated and kept in reserve until 2010, when the test crosses was experimented and were selected the pairs with the best results according to the above characters. Using the full-sib reciprocal recurrent selection, we can successfully harnessing, simultaneously, the additive and non-additive gene effects.


Author(s):  
Cedomir Radenovic ◽  
Zdravko Hojka ◽  
Dragojlo Selakovic ◽  
Miroljub Misovic ◽  
Milovan Pavlov ◽  
...  

A hypothesis that elite erect leaf maize inbred lines are characterized by properties of an efficient photo-model and that as such are very desirable in increasing the number of plants per unit area (plant density) in the process of seed production has been confirmed in the present study. The properties of the observed elite erect leaf maize inbred lines were based on the effects and characteristics of thermal processes of delayed chlorophyll fluorescence occurring in their thylakoid membranes. The temperature dependence of the delayed chlorophyll fluorescence intensity, the Arrhenius plot for the determination of phase transitions (critical temperatures) and activation energy are the principal parameters of the thermal processes. Based on the obtained results on photosynthetic properties it was also possible to estimate the tolerance and adaptation of elite erect leaf maize inbred lines to high temperatures and drought.


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