Seed production trait associations and inheritance in interspecific hybrids between Trifolium repens (white clover) and Trifolium uniflorum

2017 ◽  
Vol 68 (9) ◽  
pp. 885
Author(s):  
Muhammad Naeem ◽  
I. M. Verry ◽  
P. D. Kemp ◽  
J. P. Millner ◽  
W. M. Williams
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Trifolium Repens ◽  
Root Traits ◽  
Interspecific Hybridisation ◽  
Production Traits ◽  
Root Characteristics ◽  
Vegetative Traits ◽  
Almost All ◽  
Trait Associations

Trifolium repens L. (white clover) is an important component of temperate pastures, but its root morphology makes it vulnerable to drought and pest attack. T. uniflorum is a wild species, adapted to dry environments, with deep woody roots but poor vegetative growth and only 1–3 florets per inflorescence (head). Interspecific hybridisation to incorporate the drought tolerance and root characteristics of T. uniflorum into white clover led to primary hybrids (F1 and BC1) with poor seed production. Advanced-generation hybrids expressed high variation for almost all seed-production traits, and seed production responded to selection. To inform future breeding programs, trait associations and heritabilities were analysed. Numbers of heads per plant, florets per head and seeds per floret were important factors with moderate–high heritabilities. The derived traits, numbers of seeds per head, florets per plant and seeds per plant, expressed low–moderate heritabilities. No negative associations between seed production and root traits were found in the hybrids, nor were there any negative associations among head production, persistence and foliage production. Selection for improved seed-production traits should be effective without adversely affecting vegetative traits.

Nutrient responses and macronutrient composition of some Trifolium repens×Trifolium uniflorum interspecific hybrids

2014 ◽  
Vol 65 (4) ◽  
pp. 370 ◽  
Author(s):  
S. N. Nichols ◽  
R. W. Hofmann ◽  
W. M. Williams ◽  
J. R. Crush
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Dry Weight ◽  
Transgressive Segregation ◽  
Sand Culture ◽  
Interspecific Hybridisation ◽  
Root Characteristics ◽  
Macronutrient Composition ◽  
Soil P ◽  
Matter Production

Interspecific hybridisation is being utilised in white clover (Trifolium repens L.) breeding programs to overcome factors currently restricting productivity and persistence. Valuable new traits that may be introduced from the wild relative T. uniflorum include root characteristics and other adaptations to its natural, Mediterranean habitat. This study examined the effect of hybridisation on growth and macronutrient composition of white clover compared with T. uniflorum and T. repens × T. uniflorum backcross 1 (BC1) hybrids in two glasshouse sand culture experiments. Shoot and root dry weights of BC1 hybrids were greater than of white clover in low-concentration nutrient treatments but not in a more concentrated treatment. Decreases in dry weight with decreasing nutrient treatment strength were also smaller for some BC1 hybrids compared with white clover and other hybrid families. Most foliar macronutrient levels were adequate for white clover growth, but mean shoot or leaf phosphorus (P) concentrations were below published critical levels. Higher dry matter production under these low internal P concentrations suggests that some T. repens × T. uniflorum BC1 hybrids may be more tolerant of lower soil P levels than white clover. Such adaptations are likely to have been inherited from T. uniflorum. However, transgressive segregation may also be occurring, as T. uniflorum was larger than white clover in some, but not all, cases of low nutrient supply.

FACTORS AFFECTING SCALE OF ENTERPRISE

1985 ◽  
Vol 2 ◽  
pp. 37-40
Author(s):  
Logan Freeman
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Trifolium Repens ◽  
Factors Affecting ◽  
Alternative Crops ◽  
New Cultivars

White clover is undersown in the spring with wheat, barley and peas. Irrigation is used in order to achieve a heavy flowering in the white clover crop over one month. Three barley crops must be grown successively in some paddocks to eliminate yarrow. Lupins, peas and soybeans are alternative legumes to white clover, but white clover is still the preferred legume to grow, especially with new cultivars becoming available. Keywords: White clover, Trifolium repens, seed production, yarrow, alternative crops, overseas markets.

Phosphate responses of some Trifolium repens×T. uniflorum interspecific hybrids grown in soil

2014 ◽  
Vol 65 (4) ◽  
pp. 382 ◽  
Author(s):  
S. N. Nichols ◽  
J. R. Crush ◽  
L. Ouyang
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Interspecific Hybrids ◽  
Root Surface ◽  
P Uptake ◽  
Sand Culture ◽  
Interspecific Hybridisation ◽  
Growth Responses ◽  
Root Tips ◽  
Soil P

Previous studies in sand culture suggested that some white clover (Trifolium repens) × T. uniflorum interspecific hybrids were more tolerant than white clover of low external phosphate (P) supply. Here, P acquisition and growth responses were determined in soil for two T. repens × T. uniflorum backcross hybrids and their parental white clover cultivar, grown in a glasshouse pot experiment at Olsen P of 6, 7, 9, 14, or 20 mg P kg–1 soil. Growth of all of the clover entries responded strongly to increasing soil P levels, and one hybrid clover grew, on average, 17% better than the white clover control cultivar at Olsen soil P 9–20 mg kg–1. Internal P concentrations and shoot growth per unit P absorbed did not differ among the clovers. Instead, improved growth of the hybrid resulted from a greater ability to acquire soil P. This hybrid had the longest, most frequently branched roots. Frequent branching and growth of root tips into fresh soil would reduce the limitations to P uptake imposed by slow diffusion of P to the root surface. The results confirm previous observations that interspecific hybridisation is a useful strategy for increasing the range of P responsiveness in breeding populations for white clover.

Current issues of white clover (Trifolium repens L.) breeding, seed production and import substitution programs in Russia

2019 ◽  
Author(s):  
В. Золотарев ◽  
Н. Переправо
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Trifolium Repens ◽  
Import Substitution ◽  
Temperate Climate ◽  
Biological Traits ◽  
Forage Production ◽  
State Register ◽  
Trifolium Repens L ◽  
Clover Seed

Среди многолетних трав клевер ползучий (Trifolium repens L.) является одним из лучших бобовых компонентов для создания культурных луговых и пастбищных агрофитоценозов в районах с умеренным климатом. На основе биологических особенностей клевера ползучего показана эффективность использования этой культуры для лугопастбищного кормопроизводства страны. Дан краткий анализ опыта возделывания клевера ползучего за рубежом. Показано значение хозяйственно полезных признаков сортов на эффективность их использования в травосмесях. Приведён материал по ботанической классификации разновидностей клевера ползучего и особенностям хозяйственного использования сортов разных морфотипов. Показана различная эффективность импортных и отечественных сортов клевера при их возделывании в почвенно-климатических условиях России. В настоящее время в Государственном реестре селекционных достижений, допущенных к использованию на территории РФ, зарегистрировано 27 сортов клевера ползучего, из них девять (33) отечественной селекции. Актуализирована необходимость усиления селекционной работы по выведению новых сортов, адаптированных к разнообразным почвенно-климатическим условиям и определённым режимам пастьбы. На основании этого обозначены направления селекции. Высокий рыночный спрос вызывает необходимость организации товарного семеноводства клевера ползучего сортов отечественной селекции. Установлено, что основной объём семян завозится из-за рубежа. Однако сорта зарубежной селекции мало приспособлены для произрастания в континентальном климате России. В статье в ретроспективе показано состояние и перспективы семеноводства клевера ползучего в России, включая систему воспроизводства его семян. Представлена научно обоснованная потребность в необходимых объёмах производства посевного материала на разных этапах репродуцирования для обеспечения лугопастбищного кормопроизводства. Для существенного увеличения сборов семян клевера ползучего предложено широко внедрять в производство сортовые посевы при оптимальных технологиях их выращивания, что позволит раскрыть потенциальные возможности каждого сорта в конкретных почвенно-климатических условиях и повысить урожайность семян в 23 раза. White clover (Trifolium repens L.) is one of the best perennial legume components for grassland and pasture ecosystems in regions with temperate climate. This report describes the effectiveness of this crop in forage production basing on its biological traits. It presents the experiment on clover cultivation abroad. The influence of economically important traits is shown on clover performance in grass mixtures. The article includes white clover botanical classification and cultivation methods of different morphotypes. Performances of foreign and domestic varieties were tested under Russian environment. Currently State Register for varieties accepted for cultivation in Russia lists 27 white clover varieties, and nine of them (33) are domestic. It is important to work further on breeding of new clover varieties adapted to various conditions. There is a high demand for white clover seeds of domestic origin. The main part of white clover comes from abroad. However, such varieties poorly grow under Russian climate. This paper shows the state and perspectives of white clover seed production in Russia. When producing grassland forage efficient seed production of this crop is of great importance. Introduction of white clover varieties to particular regions is a way to stimulate its seed production using optimal cultivation techniques.

Drought resistance of Trifolium repens×Trifolium uniflorum interspecific hybrids

2014 ◽  
Vol 65 (9) ◽  
pp. 911 ◽  
Author(s):  
S. N. Nichols ◽  
R. W. Hofmann ◽  
W. M. Williams
Keyword(s):  
Water Stress ◽  
Drought Resistance ◽  
White Clover ◽  
Trifolium Repens ◽  
Dry Weight ◽  
Root Diameter ◽  
Internode Length ◽  
Lateral Spread ◽  
Interspecific Hybridisation ◽  
Leaf Lamina

White clover (Trifolium repens L.) is a widely used and highly valued temperate legume; however, its productivity and survival are restricted under dryland and drought conditions. This study investigated whether drought resistance of white clover could be improved by interspecific hybridisation with Trifolium uniflorum L. After almost 4 months without irrigation in a rain-shelter facility, shoot dry weight (DW) decreased significantly less in first-generation backcross (BC1) hybrids (–47%) than second-generation backcross (BC2) hybrids (–68%) and white clover (–69%). Stolon morphological parameters such as internode length and leaf lamina area also decreased less under water stress in the BC1 hybrids than in BC2 and white clover. There was also lower senescence in BC1 under water stress than in the other clover types. Genotypes with smaller changes in leaf lamina area, internode length, senescence and lateral spread had smaller changes in shoot DW, and there were significant correlations between constitutive levels of some characteristics and the effect of water stress on shoot DW. Under water stress, the growth form of the BC1 hybrids was compact, dense and prostrate, whereas white clover was more spreading and open. Increased allocation of dry matter to roots under drought, and greater root diameter, may also have influenced the ability of BC1 hybrids to maintain water uptake and key physiological processes. Overall, the data confirm that the drought resistance of white clover can be improved through hybridisation with T. uniflorum.

scholarly journals Relationship between Sitona lepidus larval numbers and white clover seed production

2001 ◽  
Vol 54 ◽  
pp. 141-146
Author(s):  
P.J. Gerard
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Trifolium Repens ◽  
Negative Impact ◽  
Early Flowering ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Second Year ◽  
Clover Seed ◽  
Seed Crops

Plots of two cultivars of white clover (Trifolium repens) Grasslands Prestige (smallleaved early flowering) and Grasslands Kopu (largeleaved later flowering) were established in coldframe beds Clover root weevil (Sitona lepidus) larval numbers were manipulated to obtain winter larval densities ranging from 0 to over 1000/m2 Increasing winter larval densities increased Prestige seed production (g/m2) when harvested on 28 December and 10 January and the trend was still evident on 24 January No such relationships were found in Kopu for the early and middle harvests but at the late harvest increasing winter larval densities had a negative impact on seed production The results indicate that the effect of clover root weevil larvae on second year clover seed crops may vary substantially between cultivars and may even be positive rather than negative

scholarly journals Growth of the white clover plant in relation to seed production

1980 ◽  
Vol 1 ◽  
pp. 56-63
Author(s):  
R.G. Thomas
Keyword(s):  
Key Words ◽  
Seed Production ◽  
White Clover ◽  
High Latitude ◽  
Trifolium Repens ◽  
Growth And Development ◽  
The Difference ◽  
White Clover Plant ◽  
Clover Plant

The growth and development at the stolen apex of white clover is described, particularly in relation to inflorescence initiation, and the factors controlling such initiation are reviewed for the range of cultivars which has been studied. The difference between the responses to environment in plants of Mediterranean and high latitude origin are emphasized. Key words: Trifolium repens, growth, flowering, photoperiod, temperature, seed production.

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