2004—2022 年广东审定水稻品种优质化与产量、抗性协同改良育种进展

本文简述广东省稻米市场对水稻品质要求，以及政府主管部门政策导向对水稻优质化育种的推进作用。通过收集 2004—2022 年间广东省审定的 1 101 个水稻品种的区域试验数据，统计各年审定品种达国标优质或部标优质等级的水稻品种数，并从米质指标、抗性与产量的角度对广东省优质稻育种进展进行评价。2004—2022 年广东省审定水稻品种中，106 个品种（组合）米质达到国标（部标）优质一级，占所有审定品种的 9.63%，320 个品种（组合）达国标（部标）优质二级，占所有品种的 29.06%，但早季品种优质率显著低于晚季。在所有米质性状指标中，垩白度和垩白粒率达国标（部标）优质二级以上的达标率最低，分别为 41.8%和 43.5%，早季参试品种直链淀粉含量的达标率仅 37.32%，说明这 3 个性状是新品种选育的重点改良方向。历年审定米质达国标（部标）优质二级以上品种的平均产量逐年提升，说明广东水稻优质化育种中，产量和品质实现了协同提升。国标（部标）优质二级以上的品种中，稻瘟病抗性达“中抗”以上水平的比例为 85%，白叶枯病抗性达“中抗”以上水平的比例为 22.2%。总体上杂交稻达国标（部标）优质二级以上的品种比例在提升，但较常规稻优质化育种还有较大差距。广东省水稻品种优质化率逐年提升，“优、丰、抗”的协调比例越来越好，但仍存在优化空间。培育“双抗”优质稻品种，需着力提升新品种的白叶枯病抗性水平。通过加大对地方品种等一些特异种质资源的评价利用来拓宽遗传背景，避免品种同质化，提高抗病性和抗逆性，加强传统育种和分子育种的结合，提高育种效率。     

Caprine somatic cell nuclear transfer using in vivo matured oocytes collected by laparoscopic follicular aspiration

In vivo matured oocytes collected by laparoscopic follicular aspiration (LFA) from hormone treated female goats were used as recipient ooplasts for somatic cell nuclear transfer (SCNT). Japanese native (Shiba) goats were used as donor females and some donor females were used repeatedly (two or three times) at intervals of a few months. To induce synchronization of estrus, a sponge containing 0.5 g of progesterone was inserted into the vagina of each goat for 14 days. These animals were also treated with follicle stimulating hormone (FSH) in a series of 8 injections over 4 days. The first FSH injection was administered on the morning of day 9 of sponge insertion. On the morning of day 13, 50 µg of gonadotropin‐releasing hormone (GnRH) was injected into each animal. Twenty‐nine hours after GnRH injection, LFA was performed. After removal of cumulus cells, collected oocytes with the first polar body were selected and enucleated for nuclear transfer. Anterior pituitary cells isolated from an adult male Shiba goat were transfected with a DNA fragment containing the enhanced green flourescent protein gene and the puromycin resistance gene. A single donor cell was inserted into the perivitelline space of each enucleated oocyte and fusion was induced with one electric pulse of 20 V for 10 µs. The SCNT goat eggs were cultured in chemically defined medium at 38.5°C in 5% CO₂, 5% O₂, 90% N₂ for 9 days. By LFA, 396 oocytes were collected from a total of 30 females. After removal of cumulus cells, 64% of them extruded the first polar body. The percentage of SCNT goat eggs produced using in vivo matured oocytes which developed to the blastocyst stage (20–21%) was significantly higher (P < 0.05) than that produced with in vitro matured oocytes (3–8%).     

Reactivity of secondary hydroxyl groups in methylβ-d-xylopyranoside toward aβ-o-4-type quinone methide

Methyl-d-xylopyranoside was allowed to react with-O-4-type quinone methide without a catalyst to elucidate the reactivities of secondary hydroxyl groups at the C2, C3, and C4 positions. Benzyl ether-type lignin-carbohydrate complex (LCC) compounds linked at the C2 and C4 positions were predominant, at a ratio of 23. However, the reactivity of the hydroxyl group at the C3 position was quite low. These results strongly suggest that the reactivity of the C2 hydroxyl group in xylan toward quinone methide intermediate is higher than that of the C3 hydroxyl group during biosynthesis of LCCs.     

The method for designing the profile of forest roads supported by genetic algorithm

This study examines a method for designing an optimum profile of a forest road in a short matter of time. In this method, a genetic algorithm (GA) searches for points where the gradient changes and dynamic programing (DP) designs the longitudinal slope. This method can be applied to the ground heights of an actual forest road. The evaluation function of the DP assesses the total expenditure. The inverse of this function is the fitness function. Crossover and mutation are operators of an evolution simulation of a GA. They are each repeated 20 times and 420 profiles are designed and assessed, all within about 10 min. A comparison of the profile designed by the GA with that of an actual forest road shows only one section where the formation level differed substantially. Overall, both profiles seem to show a high degree of correspondence. From this result, we believe that the profile designed by the GA is best, or the one of the best. A conventional method takes about 65 h to calculate all changing points of gradients. However, by using the GA, the calculation time was reduced to about 1/389 that of the coventional method, showing that the method which uses the GA through the profile design is very useful.     

Enantioseparation of isoxanthohumol in beer by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography

Chiral resolution of isoxanthohumol (IX) in beer samples was performed by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography. The optimum running conditions were found to be 20 mM phosphate buffer (pH 7.0) containing 45 mM hydroxypropyl-gamma-cyclodextrin and 100 mM sodium dodecyl sulfate with an effective voltage of +20 kV at 20 degrees C using direct detection at 210, 295, and 370 nm. IX was detected in 12 beer samples and the total levels of (+)- and (-)-IX ranged from 0.15 to 1.4 mg/L. But the amount of xanthohumol (XN) was below the detection limit (0.017 mg/L). Each level of (-)-IX was almost the same as that of (+)-IX, suggesting that IX was a racemic mixture in these beer samples. The racemization of IX in beer could be attributed to the production of a racemic mixture from XN during boiling and to the fact that IX enantiomers were easily interconverted.     

Adventitious root formation of Japanese cedar (Cryptomeria japonica D. Don) cuttings is stimulated by soaking basal portion of cuttings in warmed water while cooling their apical portion

To improve the propagation of Japanese cedar (Cryptomeria japonica D. Don), we investigated the effects of apical and basal temperatures during a water soaking treatment on the adventitious root formation of 70-mm long shoot tip cuttings which have an apical bud. The basal portion of the cuttings was soaked for 28 days in water with temperatures ranging from 10 to 35 °C, at an air temperature of 5 or 10 °C. Control cuttings were soaked in water at 25 °C, with an air temperature of 25 °C. Treated cuttings were then planted in vermiculite rooting medium and grown at an air temperature of 25 °C for 35 days. Adventitious roots initiated earlier and developed more in the cuttings treated with apical temperatures of 5 or 10 °C and basal temperatures of 20–30 °C than in the control cuttings. The rooting percentage was greatest (93 %) in the cuttings treated with a 10/25 °C apical/basal temperature, whereas few control cuttings rooted (13 %). This suggests that the temperature gradient created by warming the basal portion of the cuttings while cooling their apical end stimulates adventitious root formation. When we tested seasonal variation of rootability at 10/25 °C, the rooting percentage increased from early autumn to winter, and decreased from winter to summer. The soluble sugar contents did not directly affect the formation of adventitious roots in the present study.     

小麦叶片硝酸还原酶钝化蛋白的纯化与活力

通过硫酸铵分级分离和ＳｅｐｈａｄｅｘＧ－１００柱纯化得到的小麦叶片蛋白，可分为两个部分，其对硝酸还原酶（ＮＲ）都有明显的钝化活力；且钝化蛋白部分Ⅱ的钝化活力明显高于同样蛋白含量的部分Ⅰ．小麦叶片中硝酸还原酶钝化蛋白部分Ⅰ和Ⅱ同样对其根中的ＮＲ具有钝化活性。钝化蛋白部分Ⅰ通过聚丙烯酰胺凝胶电泳进一步纯化，达到电泳纯，测得分子量为４７．５ｋ