Characterization of alfalfa (Medicago sativa L.) following in vitro selection for salt tolerance     

A. Safarnejad  H. A. Collin  K. D. Bruce  T. McNeilly 《Euphytica》1996,92(1-2):55-61

Summary Alfalfa (Medicago sativa L.) is a valuable forage crop which is grown in areas of limited rainfall, high temperature and where the land is often salt affected. Seedlings of the commercial variety CUF 101 and the more salt tolerant breeding line CUF101-1S were used as explant material to produce tissue cultures for an in vitro screen for salt tolerance. Callus cultures were placed on a regeneration medium containing 0–350 mol m^-3 NaCl to establish the highest possible salt concentration that would allow buds to regenerate and survive as plantlets. Buds were regenerated in 250 mol m^-3 NaCl then isolated, grown to maturity and set seed. The response to salt tolerance in the short term was investigated by exposing 14-day-old seedlings to 200 mol m^-3 NaCl. Measurement of growth, survival, proline concentration and the activity of antioxidant enzymes were made after 14 days exposure to NaCl. One somaclone in particular (6R2IV) compared with the parent line showed increased salt tolerance, greater accumulation of proline and a greater increase in the antioxidant enzyme, glutathione reductase. A potentially important gene is pA9 which is known to be responsible for the production of a proline rich cell wall protein. Polymerase Chain Reaction (PCR) amplification of a region of the pA9 gene indicated that it was present in both tolerant and sensitive lines. Southern blotting has shown that the copy number of the pA9 was present as multiple copies in the tolerant clone compared with a single copy in the parents.Abbreviations GR glutathione reductase  相似文献   

Competition among components of synthetic varieties in alfalfa     

N. A. Fotiadis 《Euphytica》1988,37(2):167-171

Summary Eighteen alfalfa polycross progenies were tested for forage and seed yield in pure stand as well as in competition with the mixture of all progenies included in the test. The type of border affected significantly the forage and seed yield of individual progenies in one third of the cases. In most of these cases competition from the mixture resulted in reduction of the yield of individual progenies. There was no correlation between pure stand forage and seed yield, but there was significant positive correlation between forage and seed yield determined under conditions of competition. It is concluded that polycross progenies should be tested in plots bordered by the mixture of all progenies being tested.  相似文献   

Effects of Water Shortage and Air Temperature on Seed Yield and Seed Performance of Lucerne (Medicago sativa L.) in a Mediterranean Environment     

A. J. Karamanos  P. T. Papastylianou  J. Stavrou  & C. Avgoulas 《Journal of Agronomy and Crop Science》2009,195(6):408-419

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甘农1号杂花苜蓿寒地栽培技术   总被引：10，自引：4，他引：6  

曹致中  贾笃敬 《草业科学》1992,9(1):47-48

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苜蓿加工产物中未鉴定生长因子（UGF）对肉仔鸡的影响   总被引：5，自引：0，他引：5  

齐广海  林济华 《中国畜牧杂志》1994,30(1):3-4

本文研究了苜蓿加工产物中未鉴定生长因子对肉仔鸡的影响，结果表明：自制的苜蓿汁粉可以作为专用未鉴定生长因子添加剂；用苜蓿叶粉作为未鉴定生长因子来源时，应考虑其中有害成分的影响；未鉴定生长因子提高增重不是由于蛋白质存留率提高。  相似文献   

紫花苜蓿与禾草混播草地生长动态研究     

郭孝  李明 《勤云标准版测试》2007,(11)

在河南省黄河滩区土壤和气候条件下,对紫花苜蓿与无芒雀麦和羊茅二种多年生禾草的混播草地特点进行了研究,并对其地上、地下生物量的时空间动态进行了详细的分析与研究。结果表明,紫花苜蓿混播牧草地上和地下生物量季节动态均呈双峰曲线,地上生物量峰期分别在完熟期以及果后营养中期;地下生物量的峰期分别在种子完熟期和果后营养后期。地上部分生物量增长最快在抽穗期(现蕾期)到完熟期期间,紫花苜蓿与无芒雀麦以及羊茅的混播牧草的生长强度为11.92gDM/(m2·d)和14.13gDM/(m2·d);地下部分增长最快分别在分蘖期(分枝期)到拔节期(抽茎期),紫花苜蓿与无芒雀麦以及羊茅的混播牧草根系生长强度分别为8.53gDM/(m2·d)和8.94gDM/(m2·d)。  相似文献   

Volatile losses of sulfur by intact alfalfa plants     

N.J. Grundon  C.J. Asher 《Journal of plant nutrition》2013,36(12):1519-1532

An apparatus was developed for the quantitative collection of volatile sulfur compounds released by intact plants and was used to study the effects of leaf temperature and stomatal aperture on the amount and pattern of release.

An air stream sweeps volatiles released by the plants through a water‐cooled condenser system in which the air is dried prior to trapping the volatile sulfur compounds on activated carbon. Tests with ³⁵S‐labelled 1‐butanethiol gave a mean recovery of 95.8 ± 4.3%.

The yield of volatile sulfur compounds increased greatly when air flow rate increased from 1 to 2 1 min^‐1 , but was independent of flow rate over the range 2 to 6 1 min^‐1. About 93% of the trapped activity originated from plant shoots, about 1% from stem bases and roots and about 4% from culture solutions.

Release of volatile sulfur compounds from intact plants followed a diurnal pattern, maximum rates occurring around midday and minimum rates overnight. Maximum rates of release ranged from 30 to 41 ng S g dry weight of shoots^‐1 2 hr ^‐1, while minimum rates ranged from 1.5 to 2.1 ng S g dry weight of shoots^‐1 2hr^‐1. Leaf temperature rather than stomatal aperture seemed to be the major factor controlling rate of release of volatile sulfur compounds. The rate of release was almost doubled by an increase of 7–9°C in leaf temperature.  相似文献   

Effects of grain source and marginal change in lucerne hay particle size on feed sorting,eating behaviour,chewing activity,and milk production in mid‐lactation Holstein dairy cows     

S. M. Nasrollahi  G. R. Ghorbani  M. Khorvash  W. Z. Yang 《Journal of animal physiology and animal nutrition》2014,98(6):1110-1116

This study investigated the effects of grain source and lucerne hay (LH) particle length on eating behaviour, chewing activity, and milk production of lactating dairy cows. Eight Holstein dairy cows (175 ± 21 days in milk) were used in a replicated 4 × 4 Latin square design with four 21‐days periods. The experiment was a 2 × 2 factorial arrangement of treatments with barley grain alone or equal blend of barley and maize grains combined with short (15 mm) and long (30 mm) LH. Diets were fed ad libitum as total mixed ration with a concentrate to forage ratio of 60:40. Interactions between grain source and LH particle length on feed particle distributions, sorting index, chewing activity, and milk production were minimal. Partially replacing barley grain with maize in the diet overall did not change diurnal distributions of particles retained on the sieves of Penn State Particle Separator but reduced the proportion of particles on 1.18‐sieve and increased that of particles on pan (p < 0.05). Grain source did not affect sorting index and chewing activity. However, feeding long LH increased (p < 0.01) intakes of long particles retained on 19‐ and 8‐mm of sieve, prolonged (p < 0.05) eating time, and lowered eating rate (p < 0.05). Interestingly, cows fed with long LH ate more coarse particle during critical‐early time post feeding (i. e. 1.5 h), where eating time increased and eating rate decreased (p < 0.05). Increasing particle length of dietary LH tended to increase milk fat‐to‐protein ratio (p = 0.08). The results suggested that the increased eating time and decreased eating rate as a result of marginally increasing LH particle length would be beneficial to alleviate reduction of ruminal pH and milk fat percentage following the ingestion of highly fermentable diets.  相似文献   

First documented pest outbreak of the herbivorous springtail Sminthurus viridis (Collembola) in Europe          下载免费PDF全文

F. V. Crotty  R. Fychan  C. M. Benefer  D. Allen  P. Shaw  C. L. Marley 《Grass and Forage Science》2016,71(4):699-704

Sminthurus viridis (Collembola: Sminthuridae) is a native of grasslands across Europe and feeds preferentially on clover (Trifolium spp.) and lucerne (Medicago sativa), although its abundance does not normally reach damaging pest levels (as occurs in Australasia). This research note describes the first quantitative assessment of a pest outbreak of this springtail in Europe, which occurred within an existing experiment investigating the effects of cultivation practices on forage establishment. Using sticky traps to assess the incidence of S. viridis, we found a significant outbreak consisting of catches that were 10‐fold greater than background levels in nearby undamaged fields. Within the experimental area, lucerne established by direct drilling with herbicide had the highest incidence (105 (± 4·9) individuals per trap) compared to other treatments [79 (± 3·9)]. Results are discussed in terms of how cultivation practice may have imbalanced the ecosystem; for example, herbicide use may have diminished potential refugia for predators during forage establishment. This paper highlights the potential of a currently innocuous, widely established invertebrate to become present at damaging levels in agricultural crops.  相似文献   

Proteolysis and in situ ruminal degradation of lucerne ensiled with Cistus ladanifer tannins     

Maria Teresa. P. Dentinho  Ktia Paulos  Paula V. Portugal  Olga C. Moreira  Jos Santos‐Silva  Rui J. B. Bessa 《Grass and Forage Science》2019,74(1):78-85

The effects of ensiling lucerne with graded inclusion of Cistus ladanifer condensed tannins (CT) on in silo fermentative parameters, in vitro organic matter digestibility (IVOMD) and on in situ rumen degradability of dry matter (DM) and crude protein (CP) were studied. Lucerne forage ( Medicago sativa subsp. sativa ) was sprayed with different solutions of C. ladanifer CT extract in 60 ml of water in order for dose 0 (control), 40 (L40), 80 (L80) and 120 (L120) g of CT per kg of lucerne DM and was ensiled in lab‐scale silos. After 35 days, the silages were analysed for chemical composition, and the in situ ruminal degradability was determined in rams. The inclusion of CT in the silages caused an important dose‐dependent reduction in soluble‐N, NH₃‐N and a large increase in true protein content and N bound with neutral detergent fibre (NDF‐N), which indicates an effective proteolysis reduction during ensiling. Also, the rumen undegradable protein (RUP) increased linearly (P < 0.01) with CT inclusion. However, a linear decrease (P < 0.02) of 5%, 13% and 22% of IVOMD was observed for the silages L40, L80 and L120 respectively. The results obtained suggest that C. ladanifer CT can be used as silage additives to reduce proteolysis of high‐protein forages during ensiling. A level of CT of 40 g/kg DM seems to be the best compromise between the gains achieved by the protection of CP degradation in silo and in the rumen and the losses associated with the depression of the digestion and absorption.  相似文献